{"paper_id":"07b2c2d7-e68f-4782-8093-9cd056c7774c","body_text":"Feasibility of ‘Muscle Movers’: A teacher-delivered program to support children’s participation in muscle-strengthening physical activity | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Feasibility of ‘Muscle Movers’: A teacher-delivered program to support children’s participation in muscle-strengthening physical activity Jordan Smith, Sarah G. Kennedy, Narelle Eather, Nicholas Riley, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7116548/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 16 Dec, 2025 Read the published version in Pilot and Feasibility Studies → Version 1 posted 5 You are reading this latest preprint version Abstract Background: Muscle-strengthening activity (MSA) is beneficial for school-aged children, but most school-based MSA interventions have been delivered by external specialists or research staff, limiting scalability. We aimed to assess the feasibility of a teacher-delivered MSA intervention for children in advance of a future efficacy trial. Methods: We conducted a single-group feasibility trial with two Stage 2 (i.e., grade 3-4) classes from one primary school in New South Wales, Australia. The 6-week Muscle Movers intervention included: (i) enhanced PE lessons focused on foundational MSA skills (1 x 45 mins/week), (ii) classroom energiser breaks (2 x 5 mins/week), and (iii) active homework tasks (1 x 10 mins/week). We assessed acceptability, implementation, adaptation, and practicality using survey and interview methods. We also assessed pre-post change in children’s perceived strength, upper-body muscular endurance, and lower-body muscular power. Data were analysed in SPSS (V.25) using descriptive statistics and paired-samples t -tests, with Cohen’s d as a measure of effect size. Results: Two female teachers (31 and 59 years) and 30 students (mean [SD] = 9.8 [0.6] years; 40% female) were enrolled. Acceptability was high for teachers (mean [SD] = 5.0[0.0] out of 5) and students (mean [SD] = 4.1[1.0] out of 5). Teachers implemented all PE lessons, and more than double the intended energiser breaks (mean [SD] = 5.5[2.1] per week). Conversely, homework task assignment (mean [SD] = 5.0 [1.4]) and completion (mean [SD] = 2.5[0.7]) were lower than intended. Teachers reported high confidence to deliver the program and viewed it as practical and adaptable. We found a moderate increase in children’s push-up performance (mean [95%CI] = 2.2 repetitions [0.7 to 3.8]; d = 0.61), but no meaningful changes in perceived strength (mean [95%CI] = 0.1 units [-0.1 to 0.4]; d = 0.22) or standing long jump (mean [95%CI] = -1.4 cm [-7.4 to 4.7]; d = -0.09). Conclusions: Muscle Movers was feasible for classroom teachers to implement in a primary school setting. The observed improvement in students’ upper-body muscular endurance should be confirmed using an appropriately powered randomised controlled trial. Trial registration: Retrospectively registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12625000703404) strength physical education teacher intervention resistance training Figures Figure 1 Key Messages Muscle-strengthening activities (MSA) are largely neglected in school-based physical activity promotion. Of the trials that have focused on MSA, most have been delivered by external specialists or research staff, limiting their scalability. Teachers and students were highly satisfied with the ‘Muscle Movers’ program, and implementation fidelity was strong. Teachers also found the program adaptable and practical. Teachers were not affected by common barriers, including lack of time, inadequate facilities, or student motivation. Further evaluation of ‘Muscle Movers’ using an appropriately powered trial is warranted. A longer intervention period, additional teacher training, and strategies to support child engagement with home-based tasks may further support effectiveness and scalability. BACKGROUND Muscular fitness is an important marker of health for school-aged youth (1) showing cross-sectional (2) and longitudinal (3) associations with cardio-metabolic risk factors, adiposity, bone mineral density, and physical self-concept. Moreover, a sufficient level of muscular fitness is necessary for successful performance across various physical activities during youth, and this success (or lack thereof) may have important implications for confidence, motivation, and future physical activity behaviour (4) . Observational evidence of the benefits of muscular fitness is bolstered by decades of experimental work demonstrating the efficacy of muscle-strengthening activity (MSA; most commonly resistance training [RT]) for physical, psychological, and cognitive health among typically developing youth and diverse clinical populations (5-8) . For these reasons, international health authorities now recommend school-aged youth (5-17 years) participate in MSA on at least three days each week (9) . Although well supported, this advice stands in contrast to persistent beliefs among many parents and educators that MSA is either inappropriate or unnecessary for non-athletes and children (10, 11) . According to a recent meta-analysis (12) , the global prevalence of ‘guideline concordant’ MSA (i.e., 3-7 days/week) among children and adolescents is 39%, although this number varies considerably across countries (13, 14) . Considering this, it is perhaps not surprising that global secular declines in muscular fitness have been reported for children as young as 9 years (15, 16) . For example, nationally representative data demonstrate the jumping performance of Australian children aged 11-12 years has declined by approximately 11% since 1985 (17) , and two thirds of children in New South Wales (NSW) do not demonstrate a ‘healthy’ level of muscular fitness (18) . Taken together, these data imply children are participating in less MSA than they did in previous generations and less than recommended for optimal health and development. MSA participation differs according to several individual and social factors (e.g., gender, weight status, physical activity level, family support) (12) , and so there is a need for equitable interventions that can reach diverse groups of young people to redress health disparities. Schools have long been used as a setting for physical activity promotion and are generally considered equitable and cost-effective compared with other intervention settings (19) . Although many school-based interventions have targeted students’ (predominantly aerobic) moderate-to-vigorous intensity physical activity (20) , far fewer have focused on MSA. A meta-analysis published in 2022 identified 17 published studies ( N = 1,653 participants) examining the efficacy of MSA-focused school-based interventions for children (<13 years), and reported moderate pooled effects for local muscular endurance and strength/power (21) . While providing useful empirical support for the efficacy of MSA interventions in the school setting, information on intervention characteristics (e.g., delivery agent, resource provision etc) was limited. Closer inspection of the included studies shows that, while usually leveraging the school Physical Education (PE) period, interventions were rarely delivered by ‘generalist’ classroom teachers. Instead, most interventions were delivered by external providers, specialist PE teachers, or trained research staff (21) . These delivery models are either impractical or cost-prohibitive for implementation at scale. Classroom teachers are often responsible for delivering physical activity interventions in schools (22) , but many teachers consider MSA to be more complex or risky than familiar aerobic activities and games/sports (23) . Indeed, even specialist PE teachers have expressed a lack of experience and confidence to deliver MSA (23) , and this group are far more prepared than generalist teachers given the limited PE-related coursework within most pre-service teacher training programs. Generalist teachers may also experience additional logistical (i.e., lack of space/equipment) and attitudinal barriers (i.e., personal beliefs that MSA is inappropriate), which could hamper the adoption and implementation of MSA-focused programs (24) . This emphasises the need for thoughtful intervention design when promoting ‘teacher-delivered’ MSA in schools (particularly primary/elementary schools), as decisions on intervention content, complexity, space/equipment needs, requisite knowledge/training, and resourcing may all be critical. This said, even a logistically feasible and ostensibly attractive MSA intervention may fail to be adopted, properly implemented or sustained if it is viewed as competing for time with more ‘necessary’ learning (e.g., literacy and numeracy). Clearly communicating exactly ‘how’ such programs align to outcomes and content within mandatory PE curricula may thus be important for obtaining ‘buy in’ from various stakeholders (i.e., from departments of education through to individual teachers). Prior to the commitment of resources for testing efficacy/effectiveness, it is important to first establish whether an intervention is feasible within the target setting. This is particularly relevant where there is an absence of similar examples within the literature. To our knowledge, no prior trial has evaluated a curriculum-aligned MSA intervention for primary school children delivered by generalist teachers. Therefore, the aim of our study was to evaluate the feasibility of Muscle Movers , a school-based intervention to support children’s skill development and participation in MSA consistent with international recommendations. The findings from this trial will be used to identify program components in need of further refinement, and to determine whether progressing to a fully powered efficacy trial (i.e., cluster randomised controlled trial [RCT]) is warranted. METHODS Study design, participants, and setting The conduct and reporting of this study complies with the Consolidated Standards for Reporting Trials extension for randomised pilot and feasibility trials (25) . Approval for the study was obtained from the Human Research Ethics Committee of the University of Newcastle (H-2022-0273) and the Catholic Schools Office of the Diocese of Maitland-Newcastle. The intervention was evaluated using a single-group experimental design (pre-post assessments) within one Catholic primary school located in NSW, Australia. Informed consent was obtained from the school Principal, participating teachers, and parents/carers of all students prior to their enrolment in the trial. Two Stage 2 teachers (i.e., Grades 3 and 4) were recruited using a convenience sampling approach to deliver the Muscle Movers program with their classes over 6 weeks during school term 4, 2022 (Nov-Dec). Informed consent was received from the parents of almost all students in the two classes ( N = 30; consent rate = 93.8%). Baseline and post-test assessments occurred on school premises within the same school term directly prior to and following the intervention period by two unblinded researchers with postgraduate PE qualifications. Self-report student measures were collected using hard copy surveys in the classroom whereas fitness measures were conducted with small groups in a separate room. Self-report teacher measures were collected using online surveys at the same two time points. Participating teachers received a small gratuity ($100AUD) at the conclusion of the trial in recognition of their contributions to the study. Theoretical background Muscle Movers was informed by Beets and colleagues’ theory of expanded, extended, and enhanced opportunities (26) , which is a pragmatic theory that emphasises the importance of regular structured opportunities for young people to be physically active. According to this theory, interventions can increase young peoples’ physical activity by extending (increasing the duration) and enhancing (increasing the efficiency of) existing opportunities, or by expanding (creating new) opportunities for physical activity participation. Combining these strategies is expected to achieve greater improvements than might occur through any single strategy in isolation. As such, Muscle Movers targeted both expansion (energiser breaks, active homework) and enhancement (PE program) approaches to increase children’s MSA participation towards global physical activity recommendations (9) . Intervention development We used the conceptual framework by Morgan and colleagues (27) to guide intervention development. This framework outlines a targeted approach to intervention design that in the first instance considers relevant socio-cultural characteristics of end users (i.e., children and teachers) and uses these insights to inform decisions relating to four core intervention components (i.e., content, format, facilitator, pedagogy). A detailed summary of the intervention, aligned to the components of Morgan and colleagues’ conceptual model is provided in Additional file 1. The program and supporting resources were also developed with reference to the SAAFE framework (28) , which outlines five evidence-based principles intended to guide the delivery of organised physical activity sessions for school-aged youth. Guided by self-determination theory (29) , the SAAFE principles ( Supportive, Active, Autonomous, Fair, Enjoyable ) have been employed across a number of school-based programs to increase physical activity and support physical literacy whilst satisfying students’ basic psychological needs (30-32) . Intervention description A concise overview of the Muscle Movers intervention components is provided in Table 1. Muscle Movers included three distinct components intended to provide children with opportunities to participate in MSA throughout the school week: i) a curriculum-aligned PE program; ii) classroom energiser breaks; and iii) active homework tasks. These were supported by a classroom resource package developed by the research team and provided free of charge to participating teachers. The package included a teacher handbook, USB drive/Cloud drive access (for electronic resources), PE equipment pack, exercise skill cards, classroom wall charts, and student handbooks. Given the age/experience of the target population, the program aimed to build competence across four foundational bodyweight RT movement skills, considered to form the basis for more advanced RT exercises. The four movement skills, referred to within the program as the Master Moves , were given animal names to make them more engaging and memorable for children: i) Scorpion Squat , ii) Lemur Lunge , iii) Python Plank , and iv) Panther Push-up . The skills were outlined within the teacher handbook and on hard copy cards for teachers and students to use during PE lessons. The cards (see Figure 1 for example) provided an illustration of the skill, simple technique cues organised across the three phases of the movement (start, move, finish) and suggested modifications for differentiation (i.e., to increase/reduce the degree of challenge for children with differing abilities). PE program. Teachers received a prescriptive program comprised of 6-weeks of sequential PE lesson plans (1 x 45 mins/week) designed by the research team to build students’ MSA-related physical literacy. The program was linked to stage-appropriate curriculum outcomes and presented within the teacher handbook. To familiarise teachers with the PE lesson format, corresponding resources, and to model correct instruction of the four Master Moves , the first PE lesson was delivered by a member of the research team while the teacher observed. In addition, the lead researcher attended the school for one observation visit (week 3 of 6) to assess implementation fidelity, and to provide advice/support to teachers if needed. Detailed information regarding the structure and content of each PE lesson is provided in Additional file 1. Two hard copy wall posters for the classroom were provided to teachers to support PE lesson outcomes. The Managers wall chart supported teachers to allocate student helpers for transport, set-up, and pack-up of PE equipment. The Motivators wall chart supported teachers to reinforce and recognise students’ ‘self-management’ and ‘interpersonal’ skills, which along with ‘movement skills’ represent the three skill domains outlined in the NSW K-10 Personal Development, Health and Physical Education (PDHPE) syllabus (33) . Classroom energiser breaks Energiser breaks were developed by the research team to provide teachers with a scaffold for delivering additional MSA opportunities during otherwise sedentary periods of the school day. Teachers were encouraged to deliver two energiser breaks each week on days PE lessons were not delivered. Energiser breaks were developed using Microsoft PowerPoint with pre-programmed automatic transitions and provided to teachers on a USB drive (and online via a cloud-based service). Twelve unique energiser breaks were developed, organised into two formats to ensure sufficient variety and to prevent boredom. Active homework tasks To provide an additional opportunity for MSA beyond the school day, the research team developed a student handbook with six active homework tasks designed to be engaging and enjoyable for children. Teachers were instructed to assign one active homework task each week from the handbook. Tasks were designed to be brief (approx. 10 mins each), age appropriate, to promote family involvement, and to enable additional practice of the four Master Moves . Feasibility measures We used the framework outlined by Bowen and colleagues (34) to assess feasibility across the following four domains: i) acceptability, ii) implementation, iii) adaptation, iv) practicality. As the trial did not include a control group, preliminary efficacy could not be ascertained. However, we included pre-post measures for several student outcomes to determine whether changes were in the hypothesised direction. A description of the feasibility domains and list of corresponding measures is provided in Table 2. A range of quantitative feasibility measures were collected using an online survey for teachers and a hard copy survey for students. Teachers also rated each individual PE lesson activity (range; 1 = poor to 5 = excellent ) within their teacher handbook, and these data were collected at the post-test time point. Finally, after the conclusion of the intervention, the lead researcher conducted semi-structured interviews with the participating teachers to gain additional insights into their experiences delivering the program, and to seek advice on potential areas for further refinement. Interviews were audio-recorded and later transcribed by a research assistant. Teacher measures Confidence to teach muscle-strengthening activities. Assessed a scale originally developed to explore teachers’ experiences delivering PE programs (35) , but adapted to apply to teaching MSA. After reading a definition of MSA, teachers responded using a five-point Likert scale (1 = Strongly disagree , 5 = Strongly agree ) to two items assessing their confidence to teach MSA generally (e.g., “ Overall, I feel confident to teach muscle-strengthening activities to children ”), and bodyweight exercises specifically (e.g., “ I feel confident to teach exercises such as push-ups and sit-ups to children ”). Perceived barriers to teaching muscle-strengthening activities. Assessed using a scale originally developed to assess teachers’ perceptions of barriers to delivering PE but adapted to apply to MSA (36) . Teachers were asked to indicate “the degree to which the following act as barriers or inhibit your capacity to deliver muscle-strengthening activities in your school” and responded using a six-point scale (1 = No barrier or does not inhibit; 4 = Moderate barrier ; 6 = A major barrier or strongly inhibits ). The scale was comprised of 12 items clustered into two broad categories (37) . A contextual barrier composite score was calculated as the mean of responses to: i) inadequate facilities/space, ii) class size too big, iii) lack of time, iv) inadequate equipment, v) litigation concerns, and vi) lack of money budgeted to programs. An interpersonal barriers score was calculated as the mean of responses to: i) low levels of teaching confidence, ii) poor level of staff support provided, iii) low levels of personal interest and enthusiasm, iv) negative executive attitudes, v) lack of departmental assistance/professional learning, and vi) negative student attitudes. Student outcome measures Perceived strength. Assessed using the perceived strength subscale of Marsh’s Physical Self-Description Questionnaire (38) . Students responded to six items (e.g., “ I am a physically strong person” ) using a six-point scale to indicate how true each statement was for them (1 = false , 6 = true ). Given the age of the study sample (i.e., 9-10 years), response options were depicted using a spectrum of ‘smiling/frowning faces’ to aid interpretation. The internal consistency of scale items among the study sample at baseline was high (Cronbach α = 0.88). Upper body muscular endurance. Assessed using the 90-degree push-up test (39) , which is a widely used field-based test of upper body muscular endurance. Following an explanation and demonstration from the assessor, participants completed as many push-ups as possible on their toes or knees (self-selected choice) in time with a cadence set at 40 bpm. Participants’ choice of toes or knees was recorded at baseline and the same option was completed at post-test. Lower body muscular power. Assessed using the standing long jump test (40) , which is considered among the most valid and reliable field-based tests of muscular fitness for use with school-aged youth (41) . After an explanation and demonstration from the assessor, participants stood on a standing long jump mat (Toei Light®) with their toes just behind a line marked at 0cm and jumped forward as far as possible. Participants completed two test trials and the greater distance was recorded as the final result. Statistical analysis Data for acceptability, implementation, adaptation, and practicality were summarised using descriptive statistics (i.e., mean and standard deviation or counts and percentage, as appropriate). Although two classes of students were recruited, they completed the main intervention component (i.e., PE lessons) together and so were treated as a single group for analyses of pre-post change. Student outcomes were analysed using paired-samples t- tests. The study was not powered to detect statistically significant effects; therefore Cohen’s d is reported as a measure of effect size, with values of 0.2, 0.5, and 0.8 considered small, medium and large effects, respectively (42) . Interview transcripts were examined by the lead author and quotes relevant to feasibility domains identified. The lead author selected salient examples for presentation in the results section. RESULTS Two female teachers (31 and 59 years old) and 30 students (mean [SD] age = 9.8 [0.6] years, 40.0% female) were enrolled at baseline. Both teachers and all students were born in Australia and spoke English as their primary language at home. The teachers had 9 and 37 years of teaching experience, respectively, and neither had attained separate health/fitness qualifications. At baseline, teachers’ confidence to teach MSA generally (mean [SD] = 3.0 [1.4] out of 5) and bodyweight exercises specifically (mean [SD] = 3.5 [0.7] out of 5) was neutral. Of the potential barriers to delivering MSA, only two were identified as having at least a ‘moderate’ impact (i.e., mean score ≥4 out of 6). The most relevant barriers were ‘lack of departmental assistance/professional learning’ (mean [SD] = 5.0 [0.0]), ‘lack of money budgeted to programs’ (mean [SD] = 4.5 [0.7]), ‘inadequate facilities/space’ (mean [SD] = 3.5 [3.5]) and ‘inadequate equipment’ (mean [SD] = 3.5 [2.1]). Teachers generally perceived ‘contextual’ barriers (mean [SD] = 2.6 [0.4]) as more salient than ‘interpersonal’ barriers (mean [SD] = 1.9 [0.4]). Feasibility evaluation No adverse events were reported by teachers, and none of the study participants withdrew prior to the conclusion of the trial. A summary of results for teacher-reported feasibility measures is provided in Table 3 and described in detail below. Acceptability Overall, teachers and students found Muscle Movers highly acceptable. Teachers reported high overall satisfaction, would recommend the program to others, believed it benefited their students’ physical and mental health, and felt the program was supported by colleagues. Teachers also reported strong intentions to sustain delivery in future, particularly the PE and energiser break components. Teacher ratings across all PE activities were high (mean [SD] = 4.6 [0.5] out of 5), suggesting the selected activities were appropriate. Students ( n = 28 [93.3%]) similarly reported high overall enjoyment of the program (mean [SD] = 4.1 [1.0] out of 5), with the highest satisfaction for the energiser breaks (mean [SD] = 4.9 [0.3] out of 5), then PE lessons (mean [SD] = 4.1 [0.9] out of 5), and homework tasks (mean [SD] = 3.5 [1.2] out of 5). Quantitative results were supported by qualitative responses from teachers, who reiterated student engagement with the PE program, even among those not usually engaged in PE: “It was a lot of fun…the kids really were enjoying the new activities and it was moving fast but it was different things they have never done, and they really liked going back and doing it…and each week if I didn’t do those energisers it was strife…so it was really, really good.” (Grade 4 teacher, 59 years) “[Student] would have been the person to fake an injured leg prior, but she didn’t with this.” (Grade 3 teacher, 31 years) The main constructive feedback from teachers related to the desire for more PE lessons and energiser break resources, or the option to use a template to create energisers of their own tailored to students’ interests: “Yeah like a whole term’s worth [of PE lessons] would be awesome. Instead of just six.” (Grade 3 teacher, 31 years) “Yes, more of them [energiser breaks]. Or maybe even a blank where you have the exercise and teachers can put things inside the picture? That will allow us to target kids that might not really like moving cause they will show interest in them” (Grade 4 teacher, 59 years) Implementation Implementation fidelity was high for the PE lessons (6 out of 6 lessons delivered) and energiser breaks (mean [SD] = 5.5 [2.1] out of 2 breaks/week delivered) but lower for the active homework component. Teachers assigned slightly fewer tasks than intended (mean [SD] = 5.0 [1.4] out of 6) and indicated only half of students typically completed the assigned tasks. Teachers reported the program was easy to implement and indicated high confidence with program delivery. This was further supported by teachers’ post-intervention responses to the scale items, with mean (SD) increases from baseline of 2.0 (1.4) and 1.5 (0.7) for confidence to teach MSA and bodyweight exercises, respectively. Teachers also indicated no difficulty finding time for the program nor with motivating students to participate in PE lessons or energiser breaks. Some difficulty motivating students to complete homework tasks was apparent. Additional insights regarding facilitators to implementation emerged from the teacher interviews, with teachers identifying the value of the pre-prepared structure and supporting resources: “It was really good cause it was all ready for the teacher… that’s definitely a barrier… they don’t have the knowledge of how to structure it.” (Grade 3 teacher, 31 years) “…it was great that I had all the equipment so I didn’t have to hunt for it and I didn’t have to fight the fact that it had gone out on to the playground at recess and lunch and got destroyed by other kids.” (Grade 4 teacher, 59 years) Regarding the energiser breaks, one teacher identified the gender-neutral themes, music and movements as a facilitator to implementation and contributor to student engagement: “Everyone was easier to get involved because there wasn’t that gender barrier which always put me off doing brain breaks in the classroom...because I was always battling something, and I cannot cope with that.” (Grade 4 teacher, 59 years) Teachers noted the variability in student engagement with the active homework tasks, which may in part have been due to the timing of program delivery, but perhaps also insufficient guidance provided within the teacher handbook: “We started off with high participation but by the end it faded out…and I think that was more involved with not the actual activities but the fact that the school came to the end of the year and I was away for a couple of the days, and the kids are winding down and we’ve got Christmas concert practice and all that…I think that impacted it.” (Grade 4 teacher, 59 years) “Yeah, that was probably the most challenging…So I had a couple of kids, like I handed it out and like they brought it back the next day and they had done all of them… so I probably needed to explain it a bit better, you know ‘when’ they do it.” (Grade 3 teacher, 31 years) Despite the challenges, teachers identified some successes with the homework task component, including for students with additional learning needs: “I actually had comments from parents saying ‘that was great, they were so keen to do them as soon as they got home’…I noticed that it was kids with ADHD that were like ‘I love these’ and the parents as well, it got them something to do that was kind of fun homework for them rather than reading.” (Grade 3 teacher, 31 years) Adaptation and practicality Teachers perceived the program to be highly adaptable and practical, with strong ratings for the perceived quality and usage of program resources, as well as the perceived suitability of available school facilities. Of the most salient barriers to teaching MSA identified at baseline, all were lower at post-intervention; ‘lack of departmental assistance/professional learning’ (mean [SD] = 2.0 [1.4]), ‘lack of money budgeted to programs’ (mean [SD] = 1.0 [0.0]), ‘inadequate facilities/space’ (mean [SD] = 2.5 [2.1]) and ‘inadequate equipment’ (mean [SD] = 1.0 [0.0]). Moreover, the composite score for ‘contextual’ barriers was 50% lower (mean [SD] = 1.3 [0.4]) compared with baseline, and at post-intervention no specific barrier had a mean score indicating at least a ‘moderate’ impact on teaching MSA. Teachers’ qualitative responses reinforced the quantitative findings for adaptability, with one teacher noting the content of the exercise cards supporter her to adapt her delivery for a student with disability: “We have a little boy with cerebral palsy, so we adapted it for him…He just needs some extra support with that…But those ‘too easy’, ‘too hard’ things [on the exercise cards] basically did that for us.” (Grade 3 teacher, 31 years) “I adapted them [PE lessons] all the time because if it didn’t work there was always another way of adapting it to make it work.” (Grade 4 teacher, 59 years) Pre-post change in student outcomes A summary of findings for student outcomes is presented in Table 4. We observed a moderate improvement in push-ups performance (mean [95%CI] = 2.2 [0.7, 3.8] repetitions; d = 0.61). No meaningful changes were found for students’ perceived strength or standing long jump performance. DISCUSSION The aims of our study were to evaluate the feasibility of the teacher-delivered Muscle Movers intervention for primary school children. Our findings suggest the program was well-received by both teachers and students, and for teachers the intervention was viewed as practical and adaptable leading to strong implementation fidelity. Although we saw no demonstrable change in students’ perceived strength or lower body power, we did observe a potentially meaningful improvement in upper-body muscular endurance. Encouragingly both teachers and students indicated high satisfaction with Muscle Movers , including for the PE component. This is important, given the PE program accounted for the most time and was where children received explicit instruction on MSA-related skills. Both teachers delivered all intended PE lessons, rated individual PE activities highly, and appeared unaffected by common barriers to the delivery of school physical activity programs (i.e., lack of time, low self-efficacy, inadequate facilities, low student motivation) (43) . Although not tested statistically, it was encouraging that teachers’ self-reported confidence to teach MSA improved across the study period. This is despite teachers having no formal training, apart from observing the first PE lesson delivered by the lead researcher. Our positive findings for teacher confidence may be due to the consideration given to PE lesson content and supporting resources, which were designed to address common challenges experienced by generalist teachers (43) . For example, we selected familiar minor games that are enjoyable for children with diverse abilities, easy to organise and explain, and adaptable to different school environments. We also provided curriculum-aligned lesson plans within the teacher handbook to scaffold implementation and reduce teachers’ cognitive load and their planning burden. This approach was semi-prescriptive, in that we expected the Main Muscles lesson segment to be delivered as prescribed, but teachers were free to use, exclude, exchange or repeat prescribed activities from the Start Strong and Muscle-Up lesson segments based on their needs (i.e., time, space etc) and students’ preferences. These and other design choices appear to have been effective, with both teachers viewing the program as highly adaptable, the resources as high quality, and available school facilities as suitable. When designing the intervention, we recognised the implementation challenges that emerge when interventions are too rigid and cannot be adapted in reference to local contextual factors (44) . Deviations from intended intervention protocols (i.e., ‘program drift’) are one explanation for the reduction in effect size observed as physical activity interventions are scaled up (45) , a phenomenon known as the ‘scale-up penalty’ or ‘voltage drop’ (46) . In addition, pilot trials are often limited by ‘generalisability biases’, defined as the degree to which features of the intervention and sample in the pilot study are NOT scalable or generalizable to the next stage of testing in a larger efficacy/effectiveness trial (47) . Importantly, voltage drop is greatest between pilot and efficacy/effectiveness trials of (ostensibly) the same intervention when generalisability biases are present at the pilot stage. This is particularly stark in the case of changes to the delivery agent, intervention duration, or level of implementation support, all of which are associated with reductions in the standardised mean difference for the primary outcome of > 0.32 (47) . Muscle Movers was designed with scalability in mind, avoiding the risk of generalisability biases common among many past behavioural interventions for children, and allowing for teacher adaptation to address unforeseeable local constraints (48) . An interesting finding was the substantially higher than expected delivery of classroom energiser breaks. Teachers were asked to facilitate two energisers each week. In practice, teachers delivered more than twice this number, with one of the teachers at times facilitating 2–3 breaks per ‘day’. Teachers’ strong engagement with this component is consistent with a large body of research demonstrating the popularity of energisers (49, 50) , as well as their benefits for student behaviour and academic performance (51) . This said, there are barriers to implementing energiser breaks, and the characteristics of specific formats might influence their adoption by teachers (49) . Our data suggest the breaks included within Muscle Movers satisfied several criteria considered important by teachers, namely low threat to classroom control, ease of implementation, and perceived enjoyment for students (49) . The two formats of energisers we developed ensured variety, offered opportunities for student choice, and incorporated age-appropriate themes, music, and humour to promote enjoyment. Additionally, exercise intervals were based on time rather than a fixed number of repetitions to prevent unhelpful peer-comparisons of fitness, which can undermine student self-efficacy and motivation (52) . The active homework component of Muscle Movers showed mixed success and emerged as an area requiring further refinement. While intended to extend MSA opportunities beyond the school setting, homework task completion was lower than anticipated, with only around half of students engaging with the assigned activities each week. Teachers identified end-of-year timing, competing school demands, and a lack of clarity around expectations as possible barriers to implementation. Additional guidance and structure may be necessary to support teachers’ implementation and student adherence. Despite the challenges, teachers also shared successes, particularly for students with additional learning needs (e.g., those with attention deficit hyperactivity disorder) who found the tasks engaging and were motivated to involve family members. These promising accounts suggest the potential value of physically active homework, which has been shown to improve physical activity behaviour in past research (53) although generally not for activities of higher intensity (54) . The lack of oversight from teachers inherent in any ‘out-of-school time’ intervention component is likely to result in poorer adherence relative to those components within a teacher’s direct control at school. An acceptance of this reality might therefore be prudent, and lower expectations for adherence warranted. However, it is important for school-based interventions to support equity as much as possible, and so exploring effective implementation support strategies for active homework remains a worthwhile objective. We found a potentially meaningful improvement in upper body muscular endurance corresponding to a moderate effect size, but no meaningful changes in children’s perceived strength or lower body power. Care should be taken interpreting these findings given the small sample size and lack of a control group. We cannot determine whether the change in push-ups was simply a learning effect, nor whether the trivial effects for other outcomes were due to limited statistical power. This said, the push-up was one of the four Master Moves taught to and practiced by students, and so improvements in this outcome are plausible. This result is also consistent with a recent meta-analysis of school-based MSA interventions for children, which reported a moderate pooled effect (g = 0.65 [0.13 to 1.17]) for measures of local muscular endurance and a mean improvement in push-ups of 1.37 (0.91 to 1.83) repetitions among studies using this test (21) . By contrast, powerful jumping movements were not deliberately targeted in Muscle Movers , which might explain the trivial effect size for the standing long jump. In the meta-analysis by Villa-Gonzales et al, the pooled effect size for strength/power was half as large as that for muscular endurance, and trivial/non-significant among trials using the standing long jump test specifically (21) . Despite being highly valid and reliable (41) , the standing long jump may be a less appropriate outcome measure for intervention trials that do not incorporate plyometric training or maximal strength/power training. A more robust research design should be used in future to confirm or refute these speculative explanations and determine the efficacy of the program on children’s muscular fitness. Strengths and limitations A key strength of our study was the comprehensive, mixed-methods feasibility evaluation conducted with reference to the widely used framework by Bowen and colleagues (34) . In addition, Muscle Movers was designed with scalability in mind, and we tested a realistic implementation model that avoids the most common generalisability biases found within prior pilot/feasibility studies of school-based physical activity interventions. However, there are also some important limitations that should be noted. Our sample size is small, involving only two teachers and their classes from a single school, and we also did not have a control group. These limitations influence the generalisability of our feasibility results to different teachers and school contexts and limits our capacity to determine a causal link between the intervention and the positive effect on students’ local muscular endurance. In addition, the trial was not prospectively registered, and a priori progression criteria were therefore not specified. Finally, although the intervention aimed to develop students MSA-related movement skills, we did not assess this outcome, which might be more important at this stage of motor development than short-term improvements in muscular fitness. CONCLUSIONS Our study suggests that the Muscle Movers program is feasible for delivery in primary schools, as demonstrated by high teacher and student satisfaction, strong implementation fidelity, and positive teacher perceptions of adaptability and practicality. Taken together, our findings provide justification for conducting an efficacy study of the Muscle Movers program using a cluster RCT with a larger and more diverse sample of schools. A future efficacy evaluation of Muscle Movers should address areas for further refinement identified by teachers in this study, including the volume of intervention content and strategies to support student engagement with the active homework component. Moreover, a powered cluster RCT will be able to confirm the efficacy of the intervention on students’ muscular fitness, and other measures of interest not assessed in this study (e.g., MSA-related movement skill competency). Abbreviations MSA, muscle-strengthening activity NSW, New South Wales PE, physical education RT, resistance training SD, standard deviation Declarations Ethics approval and consent to participate Approval for the study was obtained from the Human Research Ethics Committee of the University of Newcastle (H-2022-0273) and the Catholic Schools Office of the Diocese of Maitland-Newcastle. Consent for publication Not applicable Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author, J.J.S., on reasonable request. Competing interests The authors declare that they have no competing interests. Funding This project was funded by a National Heart Foundation Active Australia Innovation Challenge grant. The funder had no role in the design of the study, collection, analysis and interpretation of the data, nor in the drafting or editing of the final manuscript. Authors' contributions Conceptualization: JJS, SGK, NE, NR, DRL. Methodology: JJS, SGK, NE, NR, DRL. Formal analysis: JJS, DRL. Investigation: JJS. Resources: JJS, SGK. Data curation: JJS. Writing - Original Draft: JJS. Writing - Review & Editing: JJS, SGK, NE, NR, DRL. Project administration: JJS. Funding acquisition: JJS. Acknowledgements The authors would like to thank the teachers and students at the study school for their cooperation and participation, and Dr Mark Babic for his assistance with data collection. The Hunter Medical Research Institute provides funding support for the University of Newcastle’s Centre for Active Living and Learning. DRL was supported by a National Health and Medical Research Council Future Fellowship (APP1154507). References Ortega FB, Ruiz JR, Castillo MJ, et al. Physical fitness in children and adolescence: A powerful marker of health. International Journal of Obesity . 2008;32(1):1-11. Smith JJ, Eather N, Morgan PJ, et al. The health benefits of muscular fitness for children and adolescents: A systematic review and meta-analysis. Sports Medicine . 2014;44(9):1209-23. García-Hermoso A, Ramírez-Campillo R, Izquierdo M. Is muscular fitness associated with future health benefits in children and adolescents? A systematic review and meta-analysis of longitudinal studies. Sports Medicine . 2019:1-16. Faigenbaum AD, MacDonald JP, Stracciolini A, et al. Making a strong case for prioritizing muscular fitness in youth physical activity guidelines. Current Sports Medicine Reports . 2020;19(12):530-6. Lloyd RS, Faigenbaum AD, Stone MH. Position statement on youth resistance training: the 2014 international consensus. British Journal of Sports Medicine . 2014;48(7):498-505. Kapsal NJ, Dicke T, Morin AJ, et al. Effects of physical activity on the physical and psychosocial health of youth with intellectual disabilities: A systematic review and meta-analysis. Journal of Physical Activity and Health . 2019;16(12):1187-95. Ribeiro B, Forte P, Vinhas R, et al. The benefits of resistance training in obese adolescents: A systematic review and meta-analysis. Sports Medicine-Open . 2022;8(1):1-12. Robinson K, Riley N, Owen K, et al. Effects of resistance training on academic outcomes in school-aged youth: a systematic review and meta-analysis. Sports Medicine . 2023;53(11):2095-109. Bull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine . 2020;54(24):1451-62. ten Hoor G, Sleddens EF, Kremers SP, et al. Aerobic and strength exercises for youngsters aged 12 to 15: what do parents think? BMC Public Health . 2015;15(1):1. Stricker PR, Faigenbaum AD, McCambridge TM, et al. Resistance training for children and adolescents. Pediatrics . 2020;145(6). García-Hermoso A, Muñoz-Pardeza J, Hormazábal-Aguayo I, et al. Global prevalence of compliance with muscle-strengthening activity recommendations in children and adolescents: A systematic review and meta-analysis. Available at SSRN 5151077 . Bennie JA, Faulkner G, Smith JJ. The epidemiology of muscle-strengthening activity among adolescents from 28 European countries. Scandinavian Journal of Public Health . 2022;50(2):295-302. Australian Bureau of Statistics. Physical activity [Internet]. 2022 [18 January 2025]. Available from: https://www.abs.gov.au/statistics/health/health-conditions-and-risks/physical-activity/2020-21. Tomkinson GR, Kaster T, Dooley FL, et al. Temporal trends in the standing broad jump performance of 10,940,801 children and adolescents between 1960 and 2017. Sports Medicine . 2021 2021/03/01;51(3):531-48. Kaster T, Dooley FL, Fitzgerald JS, et al. Temporal trends in the sit-ups performance of 9,939,289 children and adolescents between 1964 and 2017. Journal of sports Sciences . 2020;38(16):1913-23. Fraser BJ, Blizzard L, Tomkinson GR, et al. The great leap backward: changes in the jumping performance of Australian children aged 11−12-years between 1985 and 2015. Journal of Sports Sciences . 2019;37(7):748-54. Hardy LL, Mihrshahi S, Drayton BA, et al. NSW Schools Physical Activity and Nutrition Survey (SPANS) 2015: Full Report. Sydney: NSW Department of Health, 2016. Abu-Omar K, Rütten A, Burlacu I, et al. The cost-effectiveness of physical activity interventions: a systematic review of reviews. Preventive Medicine Reports . 2017;8:72-8. Pozuelo-Carrascosa DP, García-Hermoso A, Álvarez-Bueno C, et al. Effectiveness of school-based physical activity programmes on cardiorespiratory fitness in children: a meta-analysis of randomised controlled trials. British Journal of Sports Medicine . 2018;52(19):1234-40. Villa-González E, Barranco-Ruiz Y, García-Hermoso A, et al. Efficacy of school-based interventions for improving muscular fitness outcomes in children: A systematic review and meta-analysis. European Journal of Sport Science . 2022:1-16. Dobbins M, DeCorby K, Robeson P, et al. Cochrane review: School‐based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6‐18. Evidence‐Based Child Health: A Cochrane Review Journal . 2009;4(4):1452-561. Cox A, Noonan RJ, Fairclough SJ. PE teachers’ perceived expertise and professional development requirements in the delivery of muscular fitness activity: PE Teacher EmPOWERment Survey. European Physical Education Review . 2022:1356336X221134067. Day RE, Sahota P, Christian MS. Effective implementation of primary school-based healthy lifestyle programmes: a qualitative study of views of school staff. BMC Public Health . 2019;19(1):1-16. Eldridge SM, Chan CL, Campbell MJ, et al. CONSORT 2010 statement: extension to randomised pilot and feasibility trials. BMJ . 2016;355. Beets MW, Okely A, Weaver RG, et al. The theory of expanded, extended, and enhanced opportunities for youth physical activity promotion. International Journal of Behavioral Nutrition and Physical Activity . 2016;13(1):120. Morgan PJ, Young MD, Smith JJ, et al. Targeted health behavior interventions promoting physical activity: A conceptual model. Exercise and Sport Sciences Reviews . 2016;44(2):71-80. Lubans DR, Lonsdale C, Cohen K, et al. Framework for the design and delivery of organized physical activity sessions for children and adolescents: rationale and description of the ‘SAAFE’ teaching principles. International Journal of Behavioral Nutrition and Physical Activity . 2017;14(1):24. Deci EL, Ryan RM. The\" what\" and\" why\" of goal pursuits: Human needs and the self-determination of behavior. Psychological Inquiry . 2000;11(4):227-68. Kennedy SG, Smith JJ, Morgan PJ, et al. Implementing resistance training in secondary schools: A cluster RCT. Medicine & Science in Sports & Exercise . 2017;50(1):62-72. Lubans DR, Smith JJ, Eather N, et al. Time-efficient intervention to improve older adolescents’ cardiorespiratory fitness: findings from the ‘Burn 2 Learn’cluster randomised controlled trial. British Journal of Sports Medicine . 2021;55(13):751-8. Cohen K, Morgan PJ, Plotnikoff RC, et al. Physical activity and skills intervention: SCORES cluster randomized controlled trial. Medicine & Science in Sports & Exercise . 2015;47(4):765-74. New South Wales Education Standards Authority. Personal development, health and physical education K–10 syllabus. [Internet]. 2018. Available from: https://educationstandards.nsw.edu.au/wps/portal/nesa/k-10/learning-areas/pdhpe/pdhpe-k-10-2018. Bowen DJ, Kreuter M, Spring B, et al. How we design feasibility studies. American Journal of Preventive Medicine . 2009;36(5):452-7. Morgan P, Bourke S. Non-specialist teachers' confidence to teach PE: the nature and influence of personal school experiences in PE. Physical Education and Sport Pedagogy . 2008;13(1):1-29. Morgan PJ, Hansen V. Classroom teachers' perceptions of the impact of barriers to teaching physical education on the quality of physical education programs. Research Quarterly for Exercise and Sport . 2008;79(4):506-16. Kennedy SG, Peralta LR, Lubans DR, et al. Implementing a school-based physical activity program: process evaluation and impact on teachers’ confidence, perceived barriers and self-perceptions. Physical Education and Sport Pedagogy . 2019;24(3):233-48. Marsh HW. Physical self description questionaire: Stability and discriminant validity. Research Quarterly for Exercise and Sport . 1996;67(3):249-64. Cooper Institute for Aerobics Research. Fitnessgram: Test administration manual. Champaign, IL: Human Kinetics; 1999. Castro-Piñero J, Ortega FB, Artero EG, et al. Assessing muscular strength in youth: usefulness of standing long jump as a general index of muscular fitness. Journal of Strength and Conditioning Research . 2010;24(7):1810-7. Ortega FB, Zhang K, Cadenas-Sanchez C, et al. The Youth Fitness International Test (YFIT) battery for monitoring and surveillance among children and adolescents: A modified Delphi consensus project with 169 experts from 50 countries and territories. Journal of Sport and Health Science . 2025;14:101012. Cohen J. Statistical power for the behavioral sciences. Cohen J, editor. Hillsdale, NJ: Erlbaum; 1988. 273-88 p. Nathan N, Elton B, Babic M, et al. Barriers and facilitators to the implementation of physical activity policies in schools: a systematic review. Preventive Medicine . 2018;107:45-53. Jago R, Salway R, House D, et al. Rethinking children’s physical activity interventions at school: a new context-specific approach. Frontiers in Public Health . 2023;11:1149883. Naylor P-J, Nettlefold L, Race D, et al. Implementation of school based physical activity interventions: A systematic review. Preventive Medicine . 2015;72:95-115. Lane C, McCrabb S, Nathan N, et al. How effective are physical activity interventions when they are scaled-up: a systematic review. International Journal of Behavioral Nutrition and Physical Activity . 2021;18:1-11. Beets MW, Weaver RG, Ioannidis JP, et al. Identification and evaluation of risk of generalizability biases in pilot versus efficacy/effectiveness trials: a systematic review and meta-analysis. International Journal of Behavioral Nutrition and Physical Activity . 2020;17:1-20. McKay HA, Kennedy SG, Macdonald HM, et al. The secret sauce? Taking the mystery out of scaling-up school-based physical activity interventions. Journal of physical activity and health . 2024;1(aop):1-10. McMullen J, Kulinna P, Cothran D. Physical activity opportunities during the school day: Classroom teachers’ perceptions of using activity breaks in the classroom. Journal of teaching in physical education . 2014;33(4):511-27. Dinkel D, Schaffer C, Snyder K, et al. They just need to move: Teachers' perception of classroom physical activity breaks. Teaching and Teacher Education . 2017;63:186-95. Watson A, Timperio A, Brown H, et al. Effect of classroom-based physical activity interventions on academic and physical activity outcomes: a systematic review and meta-analysis. International Journal of Behavioral Nutrition and Physical Activity . 2017;14:1-24. Treasure DC, Robert GC. Students' perceptions of the motivational climate, achievement beliefs, and satisfaction in physical education. Research Quarterly for Exercise and Sport . 2001;72(2):165-75. Duncan S, Stewart T, McPhee J, et al. Efficacy of a compulsory homework programme for increasing physical activity and improving nutrition in children: a cluster randomised controlled trial. International Journal of Behavioral Nutrition and Physical Activity . 2019;16:1-12. Masini A, Salussolia A, Anastasia A, et al. Evaluation of school-based interventions including homework to promote healthy lifestyles: a systematic review with meta-analysis. Journal of Public Health . 2024:1-17. Tables Table 1. Intervention components, intended dose, theoretical alignment, and resources Component Weekly dose TEO strategy Supporting resources PE program 1 x 45 mins Enhancement Teacher handbook Master Move skill cards PE equipment pack Wall charts Energiser breaks 2 x 5 mins Expansion USB/cloud drive with electronic files Active homework tasks 1 x 10 mins Expansion Student handbook Table 2. Feasibility domains assessed in the current study Domain Description Student measures Teacher measures Acceptability The extent to which the program is considered suitable, satisfying, or attractive to program participants. Overall enjoyment of program Enjoyment of PE lessons Enjoyment of energiser breaks Enjoyment of homework tasks Program satisfaction Likelihood of recommending to others Intention to sustain delivery Perceived benefits for students Colleagues’ support for program Ratings of PE lesson activities Implementation The extent, likelihood, and manner in which the program can be fully implemented as planned. Number of PE lessons delivered Number of energiser breaks delivered Number of home tasks assigned and completed Perceived ease of implementation Confidence with program delivery Difficulty motivating students Adaptation The extent to which an existing program can be adapted to fit the needs of different populations. Perceived adaptability of program Practicality The extent to which the program can be delivered using existing resources or with limited resources, and without outside intervention. Use of program resources Perceived quality of program resources Suitability of school facilities Table 3. Summary of feasibility evaluation for teachers ( N = 2) Feasibility domain Survey items/measures Result a Acceptability Overall satisfaction with program (/5) 5.0 (0.0) Would recommend program to others (/5) 5.0 (0.0) Intend to sustain delivery, n (%) ‘yes’ 2 (100) Likely to deliver PE lessons again (/11) 11.0 (0.0) Likely to deliver energiser breaks again (/11) 11.0 (0.0) Likely to deliver home tasks again (/11) 9.5 (2.1) Perceived benefits to students’ physical health (/5) 5.0 (0.0) Perceived benefits to students’ mental health (/5) 5.0 (0.0) Other teachers supportive of program (/5) 5.0 (0.0) School executive supportive of program (/5) 5.0 (0.0) Mean rating for Start Strong lesson activities (/5) 4.9 (0.3) Mean rating for Main Muscles lesson activities (/5) 4.5 (0.5) Mean rating for Muscle-Up lesson activities (/5) 4.4 (0.7) Implementation Number of PE lessons delivered overall 6.0 (0.0) Number of energiser breaks delivered per week 5.5 (2.1) Number of home tasks assigned overall 5.0 (1.4) Number of home tasks students completed 2.5 (0.7) Perceived ease of implementation (/5) 5.0 (0.0) Confidence with program delivery (/5) 5.0 (0.0) Difficult finding time to implement (/5) 1.0 (0.0) Difficult to motivate students for PE lessons (/5) 1.0 (0.0) Difficult to motivate students for energisers (/5) 1.0 (0.0) Difficult to motivate students for home tasks (/5) 3.0 (1.4) Adaptation Perceived adaptability of program (/5) 5.0 (0.0) Practicality Perceived quality of program resources (/5) 5.0 (0.0) Perceived suitability of school facilities (/5) 5.0 (0.0) Used program resources for most PE lessons (/5) 5.0 (0.0) Used Managers wall chart, n (%) ‘yes’ 1 (50.0) Used Motivators wall chart, n (%) ‘yes’ 2 (100) a Values are mean and standard deviation unless otherwise specified. Table 4. Change in student outcomes Outcomes N Baseline Mean (SD) Post-test Mean (SD) Mean change (95%CI) d Perceived strength, units a 25 5.0 (0.9) 5.1 (0.9) 0.1 (-0.1, 0.4) 0.22 Push-ups, repetitions b 25 5.5 (6.7) 7.7 (7.8) 2.2 (0.7, 3.8) 0.61 Standing long jump, cm c 26 129.9 (17.8) 128.5 (17.0) -1.4 (-7.4, 4.7) -0.09 Note. CI, confidence intervals; MSA, muscle-strengthening activity; SD, standard deviation. a Five students did not provide complete data for perceived strength. b Three students were absent and two students had a precluding injury for the push-up test. c Three students were absent and one had a precluding injury for the standing long jump test. Supplementary Files Additionalfile1.docx CONSORTextensionPilotandFeasibilityTrialsChecklist.docx Cite Share Download PDF Status: Published Journal Publication published 16 Dec, 2025 Read the published version in Pilot and Feasibility Studies → Version 1 posted Reviewers agreed at journal 31 Aug, 2025 Reviewers invited by journal 28 Aug, 2025 Editor assigned by journal 11 Aug, 2025 First submitted to journal 04 Aug, 2025 Editorial decision: Major revision 14 Jul, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Of the trials that have focused on MSA, most have been delivered by external specialists or research staff, limiting their scalability.\\u003c/li\\u003e\\n \\u003cli\\u003eTeachers and students were highly satisfied with the \\u0026lsquo;Muscle Movers\\u0026rsquo; program, and implementation fidelity was strong. Teachers also found the program adaptable and practical. Teachers were not affected by common barriers, including lack of time, inadequate facilities, or student motivation.\\u003c/li\\u003e\\n \\u003cli\\u003eFurther evaluation of \\u0026lsquo;Muscle Movers\\u0026rsquo; using an appropriately powered trial is warranted. A longer intervention period, additional teacher training, and strategies to support child engagement with home-based tasks may further support effectiveness and scalability.\\u003c/li\\u003e\\n\\u003c/ul\\u003e\"},{\"header\":\"BACKGROUND\",\"content\":\"\\u003cp\\u003eMuscular fitness is an important marker of health for school-aged youth\\u003csup\\u003e(1)\\u003c/sup\\u003e showing cross-sectional\\u003csup\\u003e(2)\\u003c/sup\\u003e and longitudinal\\u003csup\\u003e(3)\\u003c/sup\\u003e associations with cardio-metabolic risk factors, adiposity, bone mineral density, and physical self-concept. Moreover, a sufficient level of muscular fitness is necessary for successful performance across various physical activities during youth, and this success (or lack thereof) may have important implications for confidence, motivation, and future physical activity behaviour\\u003csup\\u003e(4)\\u003c/sup\\u003e. Observational evidence of the benefits of muscular fitness is bolstered by decades of experimental work demonstrating the efficacy of muscle-strengthening activity (MSA; most commonly resistance training [RT]) for physical, psychological, and cognitive health among typically developing youth and diverse clinical populations \\u003csup\\u003e(5-8)\\u003c/sup\\u003e. For these reasons, international health authorities now recommend school-aged youth (5-17 years) participate in MSA on at least three days each week\\u003csup\\u003e(9)\\u003c/sup\\u003e. Although well supported, this advice stands in contrast to persistent beliefs among many parents and educators that MSA is either inappropriate or unnecessary for non-athletes and children\\u003csup\\u003e(10, 11)\\u003c/sup\\u003e.\\u003c/p\\u003e\\n\\u003cp\\u003eAccording to a recent meta-analysis\\u003csup\\u003e(12)\\u003c/sup\\u003e, the global prevalence of \\u0026lsquo;guideline concordant\\u0026rsquo; MSA (i.e., 3-7 days/week) among children and adolescents is 39%, although this number varies considerably across countries\\u003csup\\u003e(13, 14)\\u003c/sup\\u003e. Considering this, it is perhaps not surprising that global secular declines in muscular fitness have been reported for children as young as 9 years\\u003csup\\u003e(15, 16)\\u003c/sup\\u003e. For example, nationally representative data demonstrate the jumping performance of Australian children aged 11-12 years has declined by approximately 11% since 1985\\u003csup\\u003e(17)\\u003c/sup\\u003e, and two thirds of children in New South Wales (NSW) do not demonstrate a \\u0026lsquo;healthy\\u0026rsquo; level of muscular fitness\\u003csup\\u003e(18)\\u003c/sup\\u003e. Taken together, these data imply children are participating in less MSA than they did in previous generations and less than recommended for optimal health and development. MSA participation differs according to several individual and social factors (e.g., gender, weight status, physical activity level, family support)\\u003csup\\u003e(12)\\u003c/sup\\u003e, and so there is a need for equitable interventions that can reach diverse groups of young people to redress health disparities.\\u003c/p\\u003e\\n\\u003cp\\u003eSchools have long been used as a setting for physical activity promotion and are generally considered equitable and cost-effective compared with other intervention settings\\u003csup\\u003e(19)\\u003c/sup\\u003e. Although many school-based interventions have targeted students\\u0026rsquo; (predominantly aerobic) moderate-to-vigorous intensity physical activity\\u003csup\\u003e(20)\\u003c/sup\\u003e, far fewer have focused on MSA. A meta-analysis published in 2022 identified 17 published studies (\\u003cem\\u003eN\\u003c/em\\u003e = 1,653 participants) examining the efficacy of MSA-focused school-based interventions for children (\\u0026lt;13 years), and reported moderate pooled effects for local muscular endurance and strength/power\\u003csup\\u003e(21)\\u003c/sup\\u003e. While providing useful empirical support for the efficacy of MSA interventions in the school setting, information on intervention characteristics (e.g., delivery agent, resource provision etc) was limited. Closer inspection of the included studies shows that, while usually leveraging the school Physical Education (PE) period, interventions were rarely delivered by \\u0026lsquo;generalist\\u0026rsquo; classroom teachers. Instead, most interventions were delivered by external providers, specialist PE teachers, or trained research staff\\u003csup\\u003e(21)\\u003c/sup\\u003e. These delivery models are either impractical or cost-prohibitive for implementation at scale.\\u003c/p\\u003e\\n\\u003cp\\u003eClassroom teachers are often responsible for delivering physical activity interventions in schools\\u003csup\\u003e(22)\\u003c/sup\\u003e, but many teachers consider MSA to be more complex or risky than familiar aerobic activities and games/sports\\u003csup\\u003e(23)\\u003c/sup\\u003e. Indeed, even specialist PE teachers have expressed a lack of experience and confidence to deliver MSA\\u003csup\\u003e(23)\\u003c/sup\\u003e, and this group are far more prepared than generalist teachers given the limited PE-related coursework within most pre-service teacher training programs. Generalist teachers may also experience additional logistical (i.e., lack of space/equipment) and attitudinal barriers (i.e., personal beliefs that MSA is inappropriate), which could hamper the adoption and implementation of MSA-focused programs\\u003csup\\u003e(24)\\u003c/sup\\u003e. This emphasises the need for thoughtful intervention design when promoting \\u0026lsquo;teacher-delivered\\u0026rsquo; MSA in schools (particularly primary/elementary schools), as decisions on intervention content, complexity, space/equipment needs, requisite knowledge/training, and resourcing may all be critical. This said, even a logistically feasible and ostensibly attractive MSA intervention may fail to be adopted, properly implemented or sustained if it is viewed as competing for time with more \\u0026lsquo;necessary\\u0026rsquo; learning (e.g., literacy and numeracy). Clearly communicating exactly \\u0026lsquo;how\\u0026rsquo; such programs align to outcomes and content within mandatory PE curricula may thus be important for obtaining \\u0026lsquo;buy in\\u0026rsquo; from various stakeholders (i.e., from departments of education through to individual teachers).\\u003c/p\\u003e\\n\\u003cp\\u003ePrior to the commitment of resources for testing efficacy/effectiveness, it is important to first establish whether an intervention is feasible within the target setting. This is particularly relevant where there is an absence of similar examples within the literature. To our knowledge, no prior trial has evaluated a curriculum-aligned MSA intervention for primary school children delivered by generalist teachers. Therefore, the aim of our study was to evaluate the feasibility of \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e, a school-based intervention to support children\\u0026rsquo;s skill development and participation in MSA consistent with international recommendations. The findings from this trial will be used to identify program components in need of further refinement, and to determine whether progressing to a fully powered efficacy trial (i.e., cluster randomised controlled trial [RCT]) is warranted.\\u003c/p\\u003e\"},{\"header\":\"METHODS\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eStudy design, participants, and setting\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe conduct and reporting of this study complies with the Consolidated Standards for Reporting Trials extension for randomised pilot and feasibility trials\\u003csup\\u003e(25)\\u003c/sup\\u003e. Approval for the study was obtained from the Human Research Ethics Committee of the University of Newcastle (H-2022-0273) and the Catholic Schools Office of the Diocese of Maitland-Newcastle. The intervention was evaluated using a single-group experimental design (pre-post assessments) within one Catholic primary school located in NSW, Australia. Informed consent was obtained from the school Principal, participating teachers, and parents/carers of all students prior to their enrolment in the trial. Two Stage 2 teachers (i.e., Grades 3 and 4) were recruited using a convenience sampling approach to deliver the \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e program with their classes over 6 weeks during school term 4, 2022 (Nov-Dec). Informed consent was received from the parents of almost all students in the two classes (\\u003cem\\u003eN\\u003c/em\\u003e = 30; consent rate = 93.8%). Baseline and post-test assessments occurred on school premises within the same school term directly prior to and following the intervention period by two unblinded researchers with postgraduate PE qualifications. Self-report student measures were collected using hard copy surveys in the classroom whereas fitness measures were conducted with small groups in a separate room. Self-report teacher measures were collected using online surveys at the same two time points. Participating teachers received a small gratuity ($100AUD) at the conclusion of the trial in recognition of their contributions to the study.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTheoretical background\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003eMuscle Movers\\u003c/em\\u003e was informed by Beets and colleagues\\u0026rsquo; theory of expanded, extended, and enhanced opportunities\\u003csup\\u003e(26)\\u003c/sup\\u003e, which is a pragmatic theory that emphasises the importance of regular structured opportunities for young people to be physically active. According to this theory, interventions can increase young peoples\\u0026rsquo; physical activity by extending (increasing the duration) and enhancing (increasing the efficiency of) existing opportunities, or by expanding (creating new) opportunities for physical activity participation. Combining these strategies is expected to achieve greater improvements than might occur through any single strategy in isolation. As such,\\u003cem\\u003e\\u0026nbsp;Muscle Movers\\u003c/em\\u003e targeted both expansion (energiser breaks, active homework) and enhancement (PE program) approaches to increase children\\u0026rsquo;s MSA participation towards global physical activity recommendations\\u003csup\\u003e(9)\\u003c/sup\\u003e. \\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eIntervention development\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eWe used the conceptual framework by Morgan and colleagues\\u003csup\\u003e(27)\\u003c/sup\\u003e to guide intervention development. This framework outlines a targeted approach to intervention design that in the first instance considers relevant socio-cultural characteristics of end users (i.e., children and teachers) and uses these insights to inform decisions relating to four core intervention components (i.e., content, format, facilitator, pedagogy). A detailed summary of the intervention, aligned to the components of Morgan and colleagues\\u0026rsquo; conceptual model is provided in Additional file 1. The program and supporting resources were also developed with reference to the SAAFE framework\\u003csup\\u003e(28)\\u003c/sup\\u003e, which outlines five evidence-based principles intended to guide the delivery of organised physical activity sessions for school-aged youth. Guided by self-determination theory\\u003csup\\u003e(29)\\u003c/sup\\u003e, the SAAFE principles (\\u003cem\\u003eSupportive, Active, Autonomous, Fair, Enjoyable\\u003c/em\\u003e) have been employed across a number of school-based programs to increase physical activity and support physical literacy whilst satisfying students\\u0026rsquo; basic psychological needs\\u003csup\\u003e(30-32)\\u003c/sup\\u003e.\\u003cstrong\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eIntervention description\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eA concise overview of the \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e intervention components is provided in Table 1. \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e included three distinct components intended to provide children with opportunities to participate in MSA throughout the school week: i) a curriculum-aligned PE program; ii) classroom energiser breaks; and iii) active homework tasks. These were supported by a classroom resource package developed by the research team and provided free of charge to participating teachers. The package included a teacher handbook, USB drive/Cloud drive access (for electronic resources), PE equipment pack, exercise skill cards, classroom wall charts, and student handbooks. Given the age/experience of the target population, the program aimed to build competence across four foundational bodyweight RT movement skills, considered to form the basis for more advanced RT exercises. The four movement skills, referred to within the program as the \\u003cem\\u003eMaster Moves\\u003c/em\\u003e, were given animal names to make them more engaging and memorable for children: i) \\u003cem\\u003eScorpion Squat\\u003c/em\\u003e, ii) \\u003cem\\u003eLemur Lunge\\u003c/em\\u003e, iii) \\u003cem\\u003ePython Plank\\u003c/em\\u003e, and iv) \\u003cem\\u003ePanther Push-up\\u003c/em\\u003e. The skills were outlined within the teacher handbook and on hard copy cards for teachers and students to use during PE lessons. The cards (see Figure 1 for example) provided an illustration of the skill, simple technique cues organised across the three phases of the movement (start, move, finish) and suggested modifications for differentiation (i.e., to increase/reduce the degree of challenge for children with differing abilities).\\u003cu\\u003e\\u0026nbsp;\\u003c/u\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003ePE program.\\u0026nbsp;\\u003c/em\\u003e\\u003c/strong\\u003eTeachers received a prescriptive program comprised of 6-weeks of sequential PE lesson plans (1 x 45 mins/week) designed by the research team to build students\\u0026rsquo; MSA-related physical literacy. The program was linked to stage-appropriate curriculum outcomes and presented within the teacher handbook. To familiarise teachers with the PE lesson format, corresponding resources, and to model correct instruction of the four \\u003cem\\u003eMaster Moves\\u003c/em\\u003e, the first PE lesson was delivered by a member of the research team while the teacher observed. In addition, the lead researcher attended the school for one observation visit (week 3 of 6) to assess implementation fidelity, and to provide advice/support to teachers if needed. Detailed information regarding the structure and content of each PE lesson is provided in Additional file 1. Two hard copy wall posters for the classroom were provided to teachers to support PE lesson outcomes. The \\u003cem\\u003eManagers\\u003c/em\\u003e wall chart supported teachers to allocate student helpers for transport, set-up, and pack-up of PE equipment. The \\u003cem\\u003eMotivators\\u003c/em\\u003e wall chart supported teachers to reinforce and recognise students\\u0026rsquo; \\u0026lsquo;self-management\\u0026rsquo; and \\u0026lsquo;interpersonal\\u0026rsquo; skills, which along with \\u0026lsquo;movement skills\\u0026rsquo; represent the three skill domains outlined in the NSW K-10 \\u003cem\\u003ePersonal Development, Health and Physical Education (PDHPE)\\u003c/em\\u003e syllabus\\u003csup\\u003e(33)\\u003c/sup\\u003e.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eClassroom energiser breaks\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eEnergiser breaks were developed by the research team to provide teachers with a scaffold for delivering additional MSA opportunities during otherwise sedentary periods of the school day. Teachers were encouraged to deliver two energiser breaks each week on days PE lessons were not delivered. Energiser breaks were developed using Microsoft PowerPoint with pre-programmed automatic transitions and provided to teachers on a USB drive (and online via a cloud-based service). Twelve unique energiser breaks were developed, organised into two formats to ensure sufficient variety and to prevent boredom.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eActive homework tasks\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eTo provide an additional opportunity for MSA beyond the school day, the research team developed a student handbook with six active homework tasks designed to be engaging and enjoyable for children. Teachers were instructed to assign one active homework task each week from the handbook. Tasks were designed to be brief (approx. 10 mins each), age appropriate, to promote family involvement, and to enable additional practice of the four \\u003cem\\u003eMaster Moves\\u003c/em\\u003e. \\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFeasibility measures\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eWe used the framework outlined by Bowen and colleagues\\u003csup\\u003e(34)\\u003c/sup\\u003e to assess feasibility across the following four domains: i) acceptability, ii) implementation, iii) adaptation, iv) practicality. As the trial did not include a control group, preliminary efficacy could not be ascertained. However, we included pre-post measures for several student outcomes to determine whether changes were in the hypothesised direction. A description of the feasibility domains and list of corresponding measures is provided in Table 2. A range of quantitative feasibility measures were collected using an online survey for teachers and a hard copy survey for students. Teachers also rated each individual PE lesson activity (range; 1 = \\u003cem\\u003epoor\\u003c/em\\u003e to 5 = \\u003cem\\u003eexcellent\\u003c/em\\u003e) within their teacher handbook, and these data were collected at the post-test time point. Finally, after the conclusion of the intervention, the lead researcher conducted semi-structured interviews with the participating teachers to gain additional insights into their experiences delivering the program, and to seek advice on potential areas for further refinement. Interviews were audio-recorded and later transcribed by a research assistant.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTeacher measures\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eConfidence to teach muscle-strengthening activities.\\u0026nbsp;\\u003c/em\\u003e\\u003c/strong\\u003eAssessed a scale originally developed to explore teachers\\u0026rsquo; experiences delivering PE programs\\u003csup\\u003e(35)\\u003c/sup\\u003e, but adapted to apply to teaching MSA. After reading a definition of MSA, teachers responded using a five-point Likert scale (1 = \\u003cem\\u003eStrongly disagree\\u003c/em\\u003e, 5 = \\u003cem\\u003eStrongly agree\\u003c/em\\u003e) to two items assessing their confidence to teach MSA generally (e.g., \\u0026ldquo;\\u003cem\\u003eOverall, I feel confident to teach muscle-strengthening activities to children\\u003c/em\\u003e\\u0026rdquo;), and bodyweight exercises specifically (e.g., \\u0026ldquo;\\u003cem\\u003eI feel confident to teach exercises such as push-ups and sit-ups to children\\u003c/em\\u003e\\u0026rdquo;).\\u003cstrong\\u003e\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003ePerceived barriers to teaching muscle-strengthening activities.\\u0026nbsp;\\u003c/em\\u003e\\u003c/strong\\u003eAssessed using a scale originally developed to assess teachers\\u0026rsquo; perceptions of barriers to delivering PE but adapted to apply to MSA\\u003csup\\u003e(36)\\u003c/sup\\u003e. Teachers were asked to indicate\\u003cem\\u003e\\u0026nbsp;\\u0026ldquo;the degree to which the following act as barriers or inhibit your capacity to deliver muscle-strengthening activities in your school\\u0026rdquo;\\u003c/em\\u003e and\\u003cem\\u003e\\u0026nbsp;\\u003c/em\\u003eresponded using a six-point scale (1 = \\u003cem\\u003eNo barrier or does not inhibit;\\u0026nbsp;\\u003c/em\\u003e4 = \\u003cem\\u003eModerate barrier\\u003c/em\\u003e; 6 = \\u003cem\\u003eA major barrier or strongly inhibits\\u003c/em\\u003e). The scale was comprised of 12 items clustered into two broad categories\\u003csup\\u003e(37)\\u003c/sup\\u003e. A \\u003cem\\u003econtextual\\u0026nbsp;\\u003c/em\\u003ebarrier composite score was calculated as the mean of responses to: i) inadequate facilities/space, ii) class size too big, iii) lack of time, iv) inadequate equipment, v) litigation concerns, and vi) lack of money budgeted to programs. An \\u003cem\\u003einterpersonal\\u0026nbsp;\\u003c/em\\u003ebarriers score was calculated as the mean of responses to: i) low levels of teaching confidence, ii) poor level of staff support provided, iii) low levels of personal interest and enthusiasm, iv) negative executive attitudes, v) lack of departmental assistance/professional learning, and vi) negative student attitudes.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eStudent outcome measures\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003ePerceived strength.\\u0026nbsp;\\u003c/em\\u003e\\u003c/strong\\u003eAssessed using the perceived strength subscale of Marsh\\u0026rsquo;s Physical Self-Description Questionnaire\\u003csup\\u003e(38)\\u003c/sup\\u003e. Students responded to six items (e.g., \\u0026ldquo;\\u003cem\\u003eI am a physically strong person\\u0026rdquo;\\u003c/em\\u003e)\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eusing a six-point scale to indicate how true each statement was for them (1 = \\u003cem\\u003efalse\\u003c/em\\u003e, 6 = \\u003cem\\u003etrue\\u003c/em\\u003e). Given the age of the study sample (i.e., 9-10 years), response options were depicted using a spectrum of \\u0026lsquo;smiling/frowning faces\\u0026rsquo; to aid interpretation. The internal consistency of scale items among the study sample at baseline was high (Cronbach \\u0026alpha; = 0.88).\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eUpper body muscular endurance.\\u003c/em\\u003e\\u003c/strong\\u003e Assessed using the 90-degree push-up test\\u003csup\\u003e(39)\\u003c/sup\\u003e, which is a widely used field-based test of upper body muscular endurance. Following an explanation and demonstration from the assessor, participants completed as many push-ups as possible on their toes or knees (self-selected choice) in time with a cadence set at 40 bpm. Participants\\u0026rsquo; choice of toes or knees was recorded at baseline and the same option was completed at post-test. \\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eLower body muscular power.\\u0026nbsp;\\u003c/em\\u003e\\u003c/strong\\u003eAssessed using the standing long jump test\\u003csup\\u003e(40)\\u003c/sup\\u003e, which is considered among the most valid and reliable field-based tests of muscular fitness for use with school-aged youth\\u003csup\\u003e(41)\\u003c/sup\\u003e. After an explanation and demonstration from the assessor, participants stood on a standing long jump mat (Toei Light\\u0026reg;) with their toes just behind a line marked at 0cm and jumped forward as far as possible. Participants completed two test trials and the greater distance was recorded as the final result.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eStatistical analysis\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eData for acceptability, implementation, adaptation, and practicality were summarised using descriptive statistics (i.e., mean and standard deviation or counts and percentage, as appropriate). Although two classes of students were recruited, they completed the main intervention component (i.e., PE lessons) together and so were treated as a single group for analyses of pre-post change. Student outcomes were analysed using paired-samples \\u003cem\\u003et-\\u003c/em\\u003etests. The study was not powered to detect statistically significant effects; therefore Cohen\\u0026rsquo;s \\u003cem\\u003ed\\u003c/em\\u003e is reported as a measure of effect size, with values of 0.2, 0.5, and 0.8 considered small, medium and large effects, respectively\\u003csup\\u003e(42)\\u003c/sup\\u003e. Interview transcripts were examined by the lead author and quotes relevant to feasibility domains identified. The lead author selected salient examples for presentation in the results section.\\u003c/p\\u003e\"},{\"header\":\"RESULTS\",\"content\":\"\\u003cp\\u003eTwo female teachers (31 and 59 years old) and 30 students (mean [SD] age = 9.8 [0.6] years, 40.0% female) were enrolled at baseline. Both teachers and all students were born in Australia and spoke English as their primary language at home. The teachers had 9 and 37 years of teaching experience, respectively, and neither had attained separate health/fitness qualifications. At baseline, teachers\\u0026rsquo; confidence to teach MSA generally (mean [SD] = 3.0 [1.4] out of 5) and bodyweight exercises specifically (mean [SD] = 3.5 [0.7] out of 5) was neutral. Of the potential barriers to delivering MSA, only two were identified as having at least a \\u0026lsquo;moderate\\u0026rsquo; impact (i.e., mean score \\u0026ge;4 out of 6). The most relevant barriers were \\u0026lsquo;lack of departmental assistance/professional learning\\u0026rsquo; (mean [SD] = 5.0 [0.0]), \\u0026lsquo;lack of money budgeted to programs\\u0026rsquo; (mean [SD] = 4.5 [0.7]), \\u0026lsquo;inadequate facilities/space\\u0026rsquo; (mean [SD] = 3.5 [3.5]) and \\u0026lsquo;inadequate equipment\\u0026rsquo; (mean [SD] = 3.5 [2.1]). Teachers generally perceived \\u0026lsquo;contextual\\u0026rsquo; barriers (mean [SD] = 2.6 [0.4]) as more salient than \\u0026lsquo;interpersonal\\u0026rsquo; barriers (mean [SD] = 1.9 [0.4]).\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFeasibility evaluation\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eNo adverse events were reported by teachers, and none of the study participants withdrew prior to the conclusion of the trial. A summary of results for teacher-reported feasibility measures is provided in Table 3 and described in detail below.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAcceptability\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eOverall, teachers and students found \\u003cem\\u003eMuscle Movers\\u0026nbsp;\\u003c/em\\u003ehighly acceptable. Teachers reported high overall satisfaction, would recommend the program to others, believed it benefited their students\\u0026rsquo; physical and mental health, and felt the program was supported by colleagues. Teachers also reported strong intentions to sustain delivery in future, particularly the PE and energiser break components. Teacher ratings across all PE activities were high (mean [SD] = 4.6 [0.5] out of 5), suggesting the selected activities were appropriate. Students (\\u003cem\\u003en\\u003c/em\\u003e = 28 [93.3%]) similarly reported high overall enjoyment of the program (mean [SD] = 4.1 [1.0] out of 5), with the highest satisfaction for the energiser breaks (mean [SD] = 4.9 [0.3] out of 5), then PE lessons (mean [SD] = 4.1 [0.9] out of 5), and homework tasks (mean [SD] = 3.5 [1.2] out of 5). Quantitative results were supported by qualitative responses from teachers, who reiterated student engagement with the PE program, even among those not usually engaged in PE:\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;It was a lot of fun\\u0026hellip;the kids really were enjoying the new activities and it was moving fast but it was different things they have never done, and they really liked going back and doing it\\u0026hellip;and each week if I didn\\u0026rsquo;t do those energisers it was strife\\u0026hellip;so it was really, really good.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 4 teacher, 59 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;[Student] would have been the person to fake an injured leg prior, but she didn\\u0026rsquo;t with this.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 3 teacher, 31 years)\\u003c/p\\u003e\\n\\u003cp\\u003eThe main constructive feedback from teachers related to the desire for more PE lessons and energiser break resources, or the option to use a template to create energisers of their own tailored to students\\u0026rsquo; interests:\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;Yeah like a whole term\\u0026rsquo;s worth [of PE lessons] would be awesome. Instead of just six.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 3 teacher, 31 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;Yes, more of them [energiser breaks]. Or maybe even a blank where you have the exercise and teachers can put things inside the picture? That will allow us to target kids that might not really like moving cause they will show interest in them\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 4 teacher, 59 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eImplementation\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eImplementation fidelity was high for the PE lessons (6 out of 6 lessons delivered) and energiser breaks (mean [SD] = 5.5 [2.1] out of 2 breaks/week delivered) but lower for the active homework component. Teachers assigned slightly fewer tasks than intended (mean [SD] = 5.0 [1.4] out of 6) and indicated only half of students typically completed the assigned tasks. Teachers reported the program was easy to implement and indicated high confidence with program delivery. This was further supported by teachers\\u0026rsquo; post-intervention responses to the scale items, with mean (SD) increases from baseline of 2.0 (1.4) and 1.5 (0.7) for confidence to teach MSA and bodyweight exercises, respectively. Teachers also indicated no difficulty finding time for the program nor with motivating students to participate in PE lessons or energiser breaks. Some difficulty motivating students to complete homework tasks was apparent. Additional insights regarding facilitators to implementation emerged from the teacher interviews, with teachers identifying the value of the pre-prepared structure and supporting resources:\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;It was really good cause it was all ready for the teacher\\u0026hellip; that\\u0026rsquo;s definitely a barrier\\u0026hellip; they don\\u0026rsquo;t have the knowledge of how to structure it.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 3 teacher, 31 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;\\u0026hellip;it was great that I had all the equipment so I didn\\u0026rsquo;t have to hunt for it and I didn\\u0026rsquo;t have to fight the fact that it had gone out on to the playground at recess and lunch and got destroyed by other kids.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 4 teacher, 59 years)\\u003c/p\\u003e\\n\\u003cp\\u003eRegarding the energiser breaks, one teacher identified the gender-neutral themes, music and movements as a facilitator to implementation and contributor to student engagement:\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;Everyone was easier to get involved because there wasn\\u0026rsquo;t that gender barrier which always put me off doing brain breaks in the classroom...because I was always battling something, and I cannot cope with that.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 4 teacher, 59 years)\\u003c/p\\u003e\\n\\u003cp\\u003eTeachers noted the variability in student engagement with the active homework tasks, which may in part have been due to the timing of program delivery, but perhaps also insufficient guidance provided within the teacher handbook:\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;We started off with high participation but by the end it faded out\\u0026hellip;and I think that was more involved with not the actual activities but the fact that the school came to the end of the year and I was away for a couple of the days, and the kids are winding down and we\\u0026rsquo;ve got Christmas concert practice and all that\\u0026hellip;I think that impacted it.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 4 teacher, 59 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;Yeah, that was probably the most challenging\\u0026hellip;So I had a couple of kids, like I handed it out and like they brought it back the next day and they had done all of them\\u0026hellip;\\u0026nbsp;\\u003c/em\\u003e\\u003cem\\u003eso I probably needed to explain it a bit better, you know \\u0026lsquo;when\\u0026rsquo; they do it.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 3 teacher, 31 years)\\u003c/p\\u003e\\n\\u003cp\\u003eDespite the challenges, teachers identified some successes with the homework task component, including for students with additional learning needs:\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;I actually had comments from parents saying \\u0026lsquo;that was great, they were so keen to do them as soon as they got home\\u0026rsquo;\\u0026hellip;I noticed that it was kids with ADHD that were like \\u0026lsquo;I love these\\u0026rsquo; and the parents as well, it got them something to do that was kind of fun homework for them rather than reading.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 3 teacher, 31 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAdaptation and practicality\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eTeachers perceived the program to be highly adaptable and practical, with strong ratings for the perceived quality and usage of program resources, as well as the perceived suitability of available school facilities. Of the most salient barriers to teaching MSA identified at baseline, all were lower at post-intervention; \\u0026lsquo;lack of departmental assistance/professional learning\\u0026rsquo; (mean [SD] = 2.0 [1.4]), \\u0026lsquo;lack of money budgeted to programs\\u0026rsquo; (mean [SD] = 1.0 [0.0]), \\u0026lsquo;inadequate facilities/space\\u0026rsquo; (mean [SD] = 2.5 [2.1]) and \\u0026lsquo;inadequate equipment\\u0026rsquo; (mean [SD] = 1.0 [0.0]). Moreover, the composite score for \\u0026lsquo;contextual\\u0026rsquo; barriers was 50% lower (mean [SD] = 1.3 [0.4]) compared with baseline, and at post-intervention no specific barrier had a mean score indicating at least a \\u0026lsquo;moderate\\u0026rsquo; impact on teaching MSA. Teachers\\u0026rsquo; qualitative responses reinforced the quantitative findings for adaptability, with one teacher noting the content of the exercise cards supporter her to adapt her delivery for a student with disability:\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;We have a little boy with cerebral palsy, so we adapted it for him\\u0026hellip;He just needs some extra support with that\\u0026hellip;But those \\u0026lsquo;too easy\\u0026rsquo;, \\u0026lsquo;too hard\\u0026rsquo; things [on the exercise cards] basically did that for us.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 3 teacher, 31 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cem\\u003e\\u0026ldquo;I adapted them [PE lessons] all the time because if it didn\\u0026rsquo;t work there was always another way of adapting it to make it work.\\u0026rdquo;\\u0026nbsp;\\u003c/em\\u003e(Grade 4 teacher, 59 years)\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003ePre-post change in student outcomes\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eA summary of findings for student outcomes is presented in Table 4. We observed a moderate improvement in push-ups performance (mean [95%CI] = 2.2 [0.7, 3.8] repetitions; \\u003cem\\u003ed\\u003c/em\\u003e = 0.61). No meaningful changes were found for students\\u0026rsquo; perceived strength or standing long jump performance.\\u0026nbsp;\\u003c/p\\u003e\"},{\"header\":\"DISCUSSION\",\"content\":\"\\u003cp\\u003eThe aims of our study were to evaluate the feasibility of the teacher-delivered \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e intervention for primary school children. Our findings suggest the program was well-received by both teachers and students, and for teachers the intervention was viewed as practical and adaptable leading to strong implementation fidelity. Although we saw no demonstrable change in students\\u0026rsquo; perceived strength or lower body power, we did observe a potentially meaningful improvement in upper-body muscular endurance.\\u003c/p\\u003e\\u003cp\\u003eEncouragingly both teachers and students indicated high satisfaction with \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e, including for the PE component. This is important, given the PE program accounted for the most time and was where children received explicit instruction on MSA-related skills. Both teachers delivered all intended PE lessons, rated individual PE activities highly, and appeared unaffected by common barriers to the delivery of school physical activity programs (i.e., lack of time, low self-efficacy, inadequate facilities, low student motivation)\\u003csup\\u003e(43)\\u003c/sup\\u003e. Although not tested statistically, it was encouraging that teachers\\u0026rsquo; self-reported confidence to teach MSA improved across the study period. This is despite teachers having no formal training, apart from observing the first PE lesson delivered by the lead researcher.\\u003c/p\\u003e\\u003cp\\u003eOur positive findings for teacher confidence may be due to the consideration given to PE lesson content and supporting resources, which were designed to address common challenges experienced by generalist teachers\\u003csup\\u003e(43)\\u003c/sup\\u003e. For example, we selected familiar minor games that are enjoyable for children with diverse abilities, easy to organise and explain, and adaptable to different school environments. We also provided curriculum-aligned lesson plans within the teacher handbook to scaffold implementation and reduce teachers\\u0026rsquo; cognitive load and their planning burden. This approach was semi-prescriptive, in that we expected the \\u003cem\\u003eMain Muscles\\u003c/em\\u003e lesson segment to be delivered as prescribed, but teachers were free to use, exclude, exchange or repeat prescribed activities from the \\u003cem\\u003eStart Strong\\u003c/em\\u003e and \\u003cem\\u003eMuscle-Up\\u003c/em\\u003e lesson segments based on their needs (i.e., time, space etc) and students\\u0026rsquo; preferences. These and other design choices appear to have been effective, with both teachers viewing the program as highly adaptable, the resources as high quality, and available school facilities as suitable.\\u003c/p\\u003e\\u003cp\\u003eWhen designing the intervention, we recognised the implementation challenges that emerge when interventions are too rigid and cannot be adapted in reference to local contextual factors\\u003csup\\u003e(44)\\u003c/sup\\u003e. Deviations from intended intervention protocols (i.e., \\u0026lsquo;program drift\\u0026rsquo;) are one explanation for the reduction in effect size observed as physical activity interventions are scaled up\\u003csup\\u003e(45)\\u003c/sup\\u003e, a phenomenon known as the \\u0026lsquo;scale-up penalty\\u0026rsquo; or \\u0026lsquo;voltage drop\\u0026rsquo;\\u003csup\\u003e(46)\\u003c/sup\\u003e. In addition, pilot trials are often limited by \\u0026lsquo;generalisability biases\\u0026rsquo;, defined as the degree to which features of the intervention and sample in the pilot study are NOT scalable or generalizable to the next stage of testing in a larger efficacy/effectiveness trial\\u003csup\\u003e(47)\\u003c/sup\\u003e. Importantly, voltage drop is greatest between pilot and efficacy/effectiveness trials of (ostensibly) the same intervention when generalisability biases are present at the pilot stage. This is particularly stark in the case of changes to the delivery agent, intervention duration, or level of implementation support, all of which are associated with reductions in the standardised mean difference for the primary outcome of \\u0026gt;\\u0026thinsp;0.32\\u003csup\\u003e(47)\\u003c/sup\\u003e. \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e was designed with scalability in mind, avoiding the risk of generalisability biases common among many past behavioural interventions for children, and allowing for teacher adaptation to address unforeseeable local constraints\\u003csup\\u003e(48)\\u003c/sup\\u003e.\\u003c/p\\u003e\\u003cp\\u003eAn interesting finding was the substantially higher than expected delivery of classroom energiser breaks. Teachers were asked to facilitate two energisers each week. In practice, teachers delivered more than twice this number, with one of the teachers at times facilitating 2\\u0026ndash;3 breaks per \\u0026lsquo;day\\u0026rsquo;. Teachers\\u0026rsquo; strong engagement with this component is consistent with a large body of research demonstrating the popularity of energisers\\u003csup\\u003e(49, 50)\\u003c/sup\\u003e, as well as their benefits for student behaviour and academic performance\\u003csup\\u003e(51)\\u003c/sup\\u003e. This said, there are barriers to implementing energiser breaks, and the characteristics of specific formats might influence their adoption by teachers\\u003csup\\u003e(49)\\u003c/sup\\u003e. Our data suggest the breaks included within \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e satisfied several criteria considered important by teachers, namely low threat to classroom control, ease of implementation, and perceived enjoyment for students\\u003csup\\u003e(49)\\u003c/sup\\u003e. The two formats of energisers we developed ensured variety, offered opportunities for student choice, and incorporated age-appropriate themes, music, and humour to promote enjoyment. Additionally, exercise intervals were based on time rather than a fixed number of repetitions to prevent unhelpful peer-comparisons of fitness, which can undermine student self-efficacy and motivation\\u003csup\\u003e(52)\\u003c/sup\\u003e.\\u003c/p\\u003e\\u003cp\\u003eThe active homework component of \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e showed mixed success and emerged as an area requiring further refinement. While intended to extend MSA opportunities beyond the school setting, homework task completion was lower than anticipated, with only around half of students engaging with the assigned activities each week. Teachers identified end-of-year timing, competing school demands, and a lack of clarity around expectations as possible barriers to implementation. Additional guidance and structure may be necessary to support teachers\\u0026rsquo; implementation and student adherence. Despite the challenges, teachers also shared successes, particularly for students with additional learning needs (e.g., those with attention deficit hyperactivity disorder) who found the tasks engaging and were motivated to involve family members. These promising accounts suggest the potential value of physically active homework, which has been shown to improve physical activity behaviour in past research\\u003csup\\u003e(53)\\u003c/sup\\u003e although generally not for activities of higher intensity\\u003csup\\u003e(54)\\u003c/sup\\u003e. The lack of oversight from teachers inherent in any \\u0026lsquo;out-of-school time\\u0026rsquo; intervention component is likely to result in poorer adherence relative to those components within a teacher\\u0026rsquo;s direct control at school. An acceptance of this reality might therefore be prudent, and lower expectations for adherence warranted. However, it is important for school-based interventions to support equity as much as possible, and so exploring effective implementation support strategies for active homework remains a worthwhile objective.\\u003c/p\\u003e\\u003cp\\u003eWe found a potentially meaningful improvement in upper body muscular endurance corresponding to a moderate effect size, but no meaningful changes in children\\u0026rsquo;s perceived strength or lower body power. Care should be taken interpreting these findings given the small sample size and lack of a control group. We cannot determine whether the change in push-ups was simply a learning effect, nor whether the trivial effects for other outcomes were due to limited statistical power. This said, the push-up was one of the four \\u003cem\\u003eMaster Moves\\u003c/em\\u003e taught to and practiced by students, and so improvements in this outcome are plausible. This result is also consistent with a recent meta-analysis of school-based MSA interventions for children, which reported a moderate pooled effect (g\\u0026thinsp;=\\u0026thinsp;0.65 [0.13 to 1.17]) for measures of local muscular endurance and a mean improvement in push-ups of 1.37 (0.91 to 1.83) repetitions among studies using this test\\u003csup\\u003e(21)\\u003c/sup\\u003e. By contrast, powerful jumping movements were not deliberately targeted in \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e, which might explain the trivial effect size for the standing long jump. In the meta-analysis by Villa-Gonzales et al, the pooled effect size for strength/power was half as large as that for muscular endurance, and trivial/non-significant among trials using the standing long jump test specifically\\u003csup\\u003e(21)\\u003c/sup\\u003e. Despite being highly valid and reliable\\u003csup\\u003e(41)\\u003c/sup\\u003e, the standing long jump may be a less appropriate outcome measure for intervention trials that do not incorporate plyometric training or maximal strength/power training. A more robust research design should be used in future to confirm or refute these speculative explanations and determine the efficacy of the program on children\\u0026rsquo;s muscular fitness.\\u003c/p\\u003e\\u003cp\\u003e\\u003cb\\u003eStrengths and limitations\\u003c/b\\u003e\\u003c/p\\u003e\\u003cp\\u003eA key strength of our study was the comprehensive, mixed-methods feasibility evaluation conducted with reference to the widely used framework by Bowen and colleagues\\u003csup\\u003e(34)\\u003c/sup\\u003e. In addition, \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e was designed with scalability in mind, and we tested a realistic implementation model that avoids the most common generalisability biases found within prior pilot/feasibility studies of school-based physical activity interventions. However, there are also some important limitations that should be noted. Our sample size is small, involving only two teachers and their classes from a single school, and we also did not have a control group. These limitations influence the generalisability of our feasibility results to different teachers and school contexts and limits our capacity to determine a causal link between the intervention and the positive effect on students\\u0026rsquo; local muscular endurance. In addition, the trial was not prospectively registered, and \\u003cem\\u003ea priori\\u003c/em\\u003e progression criteria were therefore not specified. Finally, although the intervention aimed to develop students MSA-related movement skills, we did not assess this outcome, which might be more important at this stage of motor development than short-term improvements in muscular fitness.\\u003c/p\\u003e\"},{\"header\":\"CONCLUSIONS\",\"content\":\"\\u003cp\\u003eOur study suggests that the \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e program is feasible for delivery in primary schools, as demonstrated by high teacher and student satisfaction, strong implementation fidelity, and positive teacher perceptions of adaptability and practicality. Taken together, our findings provide justification for conducting an efficacy study of the \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e program using a cluster RCT with a larger and more diverse sample of schools. A future efficacy evaluation of \\u003cem\\u003eMuscle Movers\\u003c/em\\u003e should address areas for further refinement identified by teachers in this study, including the volume of intervention content and strategies to support student engagement with the active homework component. Moreover, a powered cluster RCT will be able to confirm the efficacy of the intervention on students\\u0026rsquo; muscular fitness, and other measures of interest not assessed in this study (e.g., MSA-related movement skill competency).\\u003c/p\\u003e\"},{\"header\":\"Abbreviations\",\"content\":\"\\u003cp\\u003eMSA, muscle-strengthening activity\\u003c/p\\u003e\\n\\u003cp\\u003eNSW, New South Wales\\u003c/p\\u003e\\n\\u003cp\\u003ePE, physical education\\u003c/p\\u003e\\n\\u003cp\\u003eRT, resistance training\\u003c/p\\u003e\\n\\u003cp\\u003eSD, standard deviation\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eEthics approval and consent to participate\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eApproval for the study was obtained from the Human Research Ethics Committee of the University of Newcastle (H-2022-0273) and the Catholic Schools Office of the Diocese of Maitland-Newcastle.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eConsent for publication\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eNot applicable\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAvailability of data and materials\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe datasets used and/or analysed during the current study are available from the corresponding author, J.J.S., on reasonable request.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eCompeting interests\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors declare that they have no competing interests.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eFunding\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThis project was funded by a National Heart Foundation Active Australia Innovation Challenge grant. The funder had no role in the design of the study, collection, analysis and interpretation of the data, nor in the drafting or editing of the final manuscript.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAuthors\\u0026apos; contributions\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eConceptualization: JJS, SGK, NE, NR, DRL. Methodology: JJS, SGK, NE, NR, DRL. Formal analysis: JJS, DRL. Investigation: JJS. Resources: JJS, SGK. Data curation: JJS. Writing - Original Draft: JJS. Writing - Review \\u0026amp; Editing: JJS, SGK, NE, NR, DRL. Project administration: JJS. Funding acquisition: JJS.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAcknowledgements\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors would like to thank the teachers and students at the study school for their cooperation and participation, and Dr Mark Babic for his assistance with data collection. The Hunter Medical Research Institute provides funding support for the University of Newcastle\\u0026rsquo;s Centre for Active Living and Learning. DRL was supported by a National Health and Medical Research Council Future Fellowship (APP1154507).\\u0026nbsp;\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003eOrtega FB, Ruiz JR, Castillo MJ, et al. Physical fitness in children and adolescence: A powerful marker of health. \\u003cem\\u003eInternational Journal of Obesity\\u003c/em\\u003e. 2008;32(1):1-11.\\u003c/li\\u003e\\n\\u003cli\\u003eSmith JJ, Eather N, Morgan PJ, et al. The health benefits of muscular fitness for children and adolescents: A systematic review and meta-analysis. \\u003cem\\u003eSports Medicine\\u003c/em\\u003e. 2014;44(9):1209-23.\\u003c/li\\u003e\\n\\u003cli\\u003eGarc\\u0026iacute;a-Hermoso A, Ram\\u0026iacute;rez-Campillo R, Izquierdo M. Is muscular fitness associated with future health benefits in children and adolescents? A systematic review and meta-analysis of longitudinal studies. \\u003cem\\u003eSports Medicine\\u003c/em\\u003e. 2019:1-16.\\u003c/li\\u003e\\n\\u003cli\\u003eFaigenbaum AD, MacDonald JP, Stracciolini A, et al. Making a strong case for prioritizing muscular fitness in youth physical activity guidelines. \\u003cem\\u003eCurrent Sports Medicine Reports\\u003c/em\\u003e. 2020;19(12):530-6.\\u003c/li\\u003e\\n\\u003cli\\u003eLloyd RS, Faigenbaum AD, Stone MH. Position statement on youth resistance training: the 2014 international consensus. \\u003cem\\u003eBritish Journal of Sports Medicine\\u003c/em\\u003e. 2014;48(7):498-505.\\u003c/li\\u003e\\n\\u003cli\\u003eKapsal NJ, Dicke T, Morin AJ, et al. Effects of physical activity on the physical and psychosocial health of youth with intellectual disabilities: A systematic review and meta-analysis. \\u003cem\\u003eJournal of Physical Activity and Health\\u003c/em\\u003e. 2019;16(12):1187-95.\\u003c/li\\u003e\\n\\u003cli\\u003eRibeiro B, Forte P, Vinhas R, et al. The benefits of resistance training in obese adolescents: A systematic review and meta-analysis. \\u003cem\\u003eSports Medicine-Open\\u003c/em\\u003e. 2022;8(1):1-12.\\u003c/li\\u003e\\n\\u003cli\\u003eRobinson K, Riley N, Owen K, et al. Effects of resistance training on academic outcomes in school-aged youth: a systematic review and meta-analysis. \\u003cem\\u003eSports Medicine\\u003c/em\\u003e. 2023;53(11):2095-109.\\u003c/li\\u003e\\n\\u003cli\\u003eBull FC, Al-Ansari SS, Biddle S, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. \\u003cem\\u003eBritish Journal of Sports Medicine\\u003c/em\\u003e. 2020;54(24):1451-62.\\u003c/li\\u003e\\n\\u003cli\\u003eten Hoor G, Sleddens EF, Kremers SP, et al. Aerobic and strength exercises for youngsters aged 12 to 15: what do parents think? \\u003cem\\u003eBMC Public Health\\u003c/em\\u003e. 2015;15(1):1.\\u003c/li\\u003e\\n\\u003cli\\u003eStricker PR, Faigenbaum AD, McCambridge TM, et al. Resistance training for children and adolescents. \\u003cem\\u003ePediatrics\\u003c/em\\u003e. 2020;145(6).\\u003c/li\\u003e\\n\\u003cli\\u003eGarc\\u0026iacute;a-Hermoso A, Mu\\u0026ntilde;oz-Pardeza J, Hormaz\\u0026aacute;bal-Aguayo I, et al. Global prevalence of compliance with muscle-strengthening activity recommendations in children and adolescents: A systematic review and meta-analysis. \\u003cem\\u003eAvailable at SSRN 5151077\\u003c/em\\u003e.\\u003c/li\\u003e\\n\\u003cli\\u003eBennie JA, Faulkner G, Smith JJ. The epidemiology of muscle-strengthening activity among adolescents from 28 European countries. \\u003cem\\u003eScandinavian Journal of Public Health\\u003c/em\\u003e. 2022;50(2):295-302.\\u003c/li\\u003e\\n\\u003cli\\u003eAustralian Bureau of Statistics. Physical activity [Internet]. 2022 [18 January 2025]. Available from: https://www.abs.gov.au/statistics/health/health-conditions-and-risks/physical-activity/2020-21.\\u003c/li\\u003e\\n\\u003cli\\u003eTomkinson GR, Kaster T, Dooley FL, et al. Temporal trends in the standing broad jump performance of 10,940,801 children and adolescents between 1960 and 2017. \\u003cem\\u003eSports Medicine\\u003c/em\\u003e. 2021 2021/03/01;51(3):531-48.\\u003c/li\\u003e\\n\\u003cli\\u003eKaster T, Dooley FL, Fitzgerald JS, et al. Temporal trends in the sit-ups performance of 9,939,289 children and adolescents between 1964 and 2017. \\u003cem\\u003eJournal of sports Sciences\\u003c/em\\u003e. 2020;38(16):1913-23.\\u003c/li\\u003e\\n\\u003cli\\u003eFraser BJ, Blizzard L, Tomkinson GR, et al. The great leap backward: changes in the jumping performance of Australian children aged 11\\u0026minus;12-years between 1985 and 2015. \\u003cem\\u003eJournal of Sports Sciences\\u003c/em\\u003e. 2019;37(7):748-54.\\u003c/li\\u003e\\n\\u003cli\\u003eHardy LL, Mihrshahi S, Drayton BA, et al. NSW Schools Physical Activity and Nutrition Survey (SPANS) 2015: Full Report. Sydney: NSW Department of Health, 2016.\\u003c/li\\u003e\\n\\u003cli\\u003eAbu-Omar K, R\\u0026uuml;tten A, Burlacu I, et al. The cost-effectiveness of physical activity interventions: a systematic review of reviews. \\u003cem\\u003ePreventive Medicine Reports\\u003c/em\\u003e. 2017;8:72-8.\\u003c/li\\u003e\\n\\u003cli\\u003ePozuelo-Carrascosa DP, Garc\\u0026iacute;a-Hermoso A, \\u0026Aacute;lvarez-Bueno C, et al. Effectiveness of school-based physical activity programmes on cardiorespiratory fitness in children: a meta-analysis of randomised controlled trials. \\u003cem\\u003eBritish Journal of Sports Medicine\\u003c/em\\u003e. 2018;52(19):1234-40.\\u003c/li\\u003e\\n\\u003cli\\u003eVilla-Gonz\\u0026aacute;lez E, Barranco-Ruiz Y, Garc\\u0026iacute;a-Hermoso A, et al. Efficacy of school-based interventions for improving muscular fitness outcomes in children: A systematic review and meta-analysis. \\u003cem\\u003eEuropean Journal of Sport Science\\u003c/em\\u003e. 2022:1-16.\\u003c/li\\u003e\\n\\u003cli\\u003eDobbins M, DeCorby K, Robeson P, et al. Cochrane review: School‐based physical activity programs for promoting physical activity and fitness in children and adolescents aged 6‐18. \\u003cem\\u003eEvidence‐Based Child Health: A Cochrane Review Journal\\u003c/em\\u003e. 2009;4(4):1452-561.\\u003c/li\\u003e\\n\\u003cli\\u003eCox A, Noonan RJ, Fairclough SJ. PE teachers\\u0026rsquo; perceived expertise and professional development requirements in the delivery of muscular fitness activity: PE Teacher EmPOWERment Survey. \\u003cem\\u003eEuropean Physical Education Review\\u003c/em\\u003e. 2022:1356336X221134067.\\u003c/li\\u003e\\n\\u003cli\\u003eDay RE, Sahota P, Christian MS. Effective implementation of primary school-based healthy lifestyle programmes: a qualitative study of views of school staff. \\u003cem\\u003eBMC Public Health\\u003c/em\\u003e. 2019;19(1):1-16.\\u003c/li\\u003e\\n\\u003cli\\u003eEldridge SM, Chan CL, Campbell MJ, et al. CONSORT 2010 statement: extension to randomised pilot and feasibility trials. \\u003cem\\u003eBMJ\\u003c/em\\u003e. 2016;355.\\u003c/li\\u003e\\n\\u003cli\\u003eBeets MW, Okely A, Weaver RG, et al. The theory of expanded, extended, and enhanced opportunities for youth physical activity promotion. \\u003cem\\u003eInternational Journal of Behavioral Nutrition and Physical Activity\\u003c/em\\u003e. 2016;13(1):120.\\u003c/li\\u003e\\n\\u003cli\\u003eMorgan PJ, Young MD, Smith JJ, et al. Targeted health behavior interventions promoting physical activity: A conceptual model. \\u003cem\\u003eExercise and Sport Sciences Reviews\\u003c/em\\u003e. 2016;44(2):71-80.\\u003c/li\\u003e\\n\\u003cli\\u003eLubans DR, Lonsdale C, Cohen K, et al. Framework for the design and delivery of organized physical activity sessions for children and adolescents: rationale and description of the \\u0026lsquo;SAAFE\\u0026rsquo; teaching principles. \\u003cem\\u003eInternational Journal of Behavioral Nutrition and Physical Activity\\u003c/em\\u003e. 2017;14(1):24.\\u003c/li\\u003e\\n\\u003cli\\u003eDeci EL, Ryan RM. The\\u0026quot; what\\u0026quot; and\\u0026quot; why\\u0026quot; of goal pursuits: Human needs and the self-determination of behavior. \\u003cem\\u003ePsychological Inquiry\\u003c/em\\u003e. 2000;11(4):227-68.\\u003c/li\\u003e\\n\\u003cli\\u003eKennedy SG, Smith JJ, Morgan PJ, et al. Implementing resistance training in secondary schools: A cluster RCT. \\u003cem\\u003eMedicine \\u0026amp; Science in Sports \\u0026amp; Exercise\\u003c/em\\u003e. 2017;50(1):62-72.\\u003c/li\\u003e\\n\\u003cli\\u003eLubans DR, Smith JJ, Eather N, et al. Time-efficient intervention to improve older adolescents\\u0026rsquo; cardiorespiratory fitness: findings from the \\u0026lsquo;Burn 2 Learn\\u0026rsquo;cluster randomised controlled trial. \\u003cem\\u003eBritish Journal of Sports Medicine\\u003c/em\\u003e. 2021;55(13):751-8.\\u003c/li\\u003e\\n\\u003cli\\u003eCohen K, Morgan PJ, Plotnikoff RC, et al. Physical activity and skills intervention: SCORES cluster randomized controlled trial. \\u003cem\\u003eMedicine \\u0026amp; Science in Sports \\u0026amp; Exercise\\u003c/em\\u003e. 2015;47(4):765-74.\\u003c/li\\u003e\\n\\u003cli\\u003eNew South Wales Education Standards Authority. Personal development, health and physical education K\\u0026ndash;10 syllabus. [Internet]. 2018. Available from: https://educationstandards.nsw.edu.au/wps/portal/nesa/k-10/learning-areas/pdhpe/pdhpe-k-10-2018.\\u003c/li\\u003e\\n\\u003cli\\u003eBowen DJ, Kreuter M, Spring B, et al. How we design feasibility studies. \\u003cem\\u003eAmerican Journal of Preventive Medicine\\u003c/em\\u003e. 2009;36(5):452-7.\\u003c/li\\u003e\\n\\u003cli\\u003eMorgan P, Bourke S. Non-specialist teachers\\u0026apos; confidence to teach PE: the nature and influence of personal school experiences in PE. \\u003cem\\u003ePhysical Education and Sport Pedagogy\\u003c/em\\u003e. 2008;13(1):1-29.\\u003c/li\\u003e\\n\\u003cli\\u003eMorgan PJ, Hansen V. Classroom teachers\\u0026apos; perceptions of the impact of barriers to teaching physical education on the quality of physical education programs. \\u003cem\\u003eResearch Quarterly for Exercise and Sport\\u003c/em\\u003e. 2008;79(4):506-16.\\u003c/li\\u003e\\n\\u003cli\\u003eKennedy SG, Peralta LR, Lubans DR, et al. Implementing a school-based physical activity program: process evaluation and impact on teachers\\u0026rsquo; confidence, perceived barriers and self-perceptions. \\u003cem\\u003ePhysical Education and Sport Pedagogy\\u003c/em\\u003e. 2019;24(3):233-48.\\u003c/li\\u003e\\n\\u003cli\\u003eMarsh HW. Physical self description questionaire: Stability and discriminant validity. \\u003cem\\u003eResearch Quarterly for Exercise and Sport\\u003c/em\\u003e. 1996;67(3):249-64.\\u003c/li\\u003e\\n\\u003cli\\u003eCooper Institute for Aerobics Research. Fitnessgram: Test administration manual. Champaign, IL: Human Kinetics; 1999.\\u003c/li\\u003e\\n\\u003cli\\u003eCastro-Pi\\u0026ntilde;ero J, Ortega FB, Artero EG, et al. Assessing muscular strength in youth: usefulness of standing long jump as a general index of muscular fitness. \\u003cem\\u003eJournal of Strength and Conditioning Research\\u003c/em\\u003e. 2010;24(7):1810-7.\\u003c/li\\u003e\\n\\u003cli\\u003eOrtega FB, Zhang K, Cadenas-Sanchez C, et al. The Youth Fitness International Test (YFIT) battery for monitoring and surveillance among children and adolescents: A modified Delphi consensus project with 169 experts from 50 countries and territories. \\u003cem\\u003eJournal of Sport and Health Science\\u003c/em\\u003e. 2025;14:101012.\\u003c/li\\u003e\\n\\u003cli\\u003eCohen J. Statistical power for the behavioral sciences. Cohen J, editor. Hillsdale, NJ: Erlbaum; 1988. 273-88 p.\\u003c/li\\u003e\\n\\u003cli\\u003eNathan N, Elton B, Babic M, et al. Barriers and facilitators to the implementation of physical activity policies in schools: a systematic review. \\u003cem\\u003ePreventive Medicine\\u003c/em\\u003e. 2018;107:45-53.\\u003c/li\\u003e\\n\\u003cli\\u003eJago R, Salway R, House D, et al. Rethinking children\\u0026rsquo;s physical activity interventions at school: a new context-specific approach. \\u003cem\\u003eFrontiers in Public Health\\u003c/em\\u003e. 2023;11:1149883.\\u003c/li\\u003e\\n\\u003cli\\u003eNaylor P-J, Nettlefold L, Race D, et al. Implementation of school based physical activity interventions: A systematic review. \\u003cem\\u003ePreventive Medicine\\u003c/em\\u003e. 2015;72:95-115.\\u003c/li\\u003e\\n\\u003cli\\u003eLane C, McCrabb S, Nathan N, et al. How effective are physical activity interventions when they are scaled-up: a systematic review. \\u003cem\\u003eInternational Journal of Behavioral Nutrition and Physical Activity\\u003c/em\\u003e. 2021;18:1-11.\\u003c/li\\u003e\\n\\u003cli\\u003eBeets MW, Weaver RG, Ioannidis JP, et al. Identification and evaluation of risk of generalizability biases in pilot versus efficacy/effectiveness trials: a systematic review and meta-analysis. \\u003cem\\u003eInternational Journal of Behavioral Nutrition and Physical Activity\\u003c/em\\u003e. 2020;17:1-20.\\u003c/li\\u003e\\n\\u003cli\\u003eMcKay HA, Kennedy SG, Macdonald HM, et al. The secret sauce? Taking the mystery out of scaling-up school-based physical activity interventions. \\u003cem\\u003eJournal of physical activity and health\\u003c/em\\u003e. 2024;1(aop):1-10.\\u003c/li\\u003e\\n\\u003cli\\u003eMcMullen J, Kulinna P, Cothran D. Physical activity opportunities during the school day: Classroom teachers\\u0026rsquo; perceptions of using activity breaks in the classroom. \\u003cem\\u003eJournal of teaching in physical education\\u003c/em\\u003e. 2014;33(4):511-27.\\u003c/li\\u003e\\n\\u003cli\\u003eDinkel D, Schaffer C, Snyder K, et al. They just need to move: Teachers\\u0026apos; perception of classroom physical activity breaks. \\u003cem\\u003eTeaching and Teacher Education\\u003c/em\\u003e. 2017;63:186-95.\\u003c/li\\u003e\\n\\u003cli\\u003eWatson A, Timperio A, Brown H, et al. Effect of classroom-based physical activity interventions on academic and physical activity outcomes: a systematic review and meta-analysis. \\u003cem\\u003eInternational Journal of Behavioral Nutrition and Physical Activity\\u003c/em\\u003e. 2017;14:1-24.\\u003c/li\\u003e\\n\\u003cli\\u003eTreasure DC, Robert GC. Students\\u0026apos; perceptions of the motivational climate, achievement beliefs, and satisfaction in physical education. \\u003cem\\u003eResearch Quarterly for Exercise and Sport\\u003c/em\\u003e. 2001;72(2):165-75.\\u003c/li\\u003e\\n\\u003cli\\u003eDuncan S, Stewart T, McPhee J, et al. Efficacy of a compulsory homework programme for increasing physical activity and improving nutrition in children: a cluster randomised controlled trial. \\u003cem\\u003eInternational Journal of Behavioral Nutrition and Physical Activity\\u003c/em\\u003e. 2019;16:1-12.\\u003c/li\\u003e\\n\\u003cli\\u003eMasini A, Salussolia A, Anastasia A, et al. Evaluation of school-based interventions including homework to promote healthy lifestyles: a systematic review with meta-analysis. \\u003cem\\u003eJournal of Public Health\\u003c/em\\u003e. 2024:1-17.\\u003c/li\\u003e\\n\\u003c/ol\\u003e\"},{\"header\":\"Tables\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eTable 1.\\u0026nbsp;\\u003c/strong\\u003eIntervention components, intended dose, theoretical alignment, and resources\\u003c/p\\u003e\\n\\u003ctable border=\\\"1\\\" cellspacing=\\\"0\\\" cellpadding=\\\"0\\\" width=\\\"586\\\"\\u003e\\n \\u003ctbody\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 161px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eComponent\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 95px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eWeekly dose\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eTEO strategy\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 227px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eSupporting resources\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 161px;\\\"\\u003e\\n \\u003cp\\u003ePE program\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 95px;\\\"\\u003e\\n \\u003cp\\u003e1 x 45 mins\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003eEnhancement\\u003c/p\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 227px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003eTeacher handbook\\u003c/li\\u003e\\n \\u003cli\\u003eMaster Move skill cards\\u003c/li\\u003e\\n \\u003cli\\u003ePE equipment pack\\u003c/li\\u003e\\n \\u003cli\\u003eWall charts\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 161px;\\\"\\u003e\\n \\u003cp\\u003eEnergiser breaks\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 95px;\\\"\\u003e\\n \\u003cp\\u003e2 x 5 mins\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003eExpansion\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 227px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003eUSB/cloud drive with electronic files\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 161px;\\\"\\u003e\\n \\u003cp\\u003eActive homework tasks\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 95px;\\\"\\u003e\\n \\u003cp\\u003e1 x 10 mins\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003eExpansion\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 227px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003eStudent handbook\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003cbr\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 2.\\u0026nbsp;\\u003c/strong\\u003eFeasibility domains assessed in the current study\\u003c/p\\u003e\\n\\u003ctable border=\\\"1\\\" cellspacing=\\\"0\\\" cellpadding=\\\"0\\\"\\u003e\\n \\u003ctbody\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 113px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eDomain\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 312px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eDescription\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 236px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eStudent measures\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 265px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eTeacher measures\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 113px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eAcceptability\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 312px;\\\"\\u003e\\n \\u003cp\\u003eThe extent to which the program is considered suitable, satisfying, or attractive to program participants.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 236px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003eOverall enjoyment of program\\u0026nbsp;\\u003c/li\\u003e\\n \\u003cli\\u003eEnjoyment of PE lessons\\u003c/li\\u003e\\n \\u003cli\\u003eEnjoyment of energiser breaks\\u003c/li\\u003e\\n \\u003cli\\u003eEnjoyment of homework tasks\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 265px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003eProgram satisfaction\\u003c/li\\u003e\\n \\u003cli\\u003eLikelihood of recommending to others\\u003c/li\\u003e\\n \\u003cli\\u003eIntention to sustain delivery\\u003c/li\\u003e\\n \\u003cli\\u003ePerceived benefits for students\\u003c/li\\u003e\\n \\u003cli\\u003eColleagues\\u0026rsquo; support for program\\u003c/li\\u003e\\n \\u003cli\\u003eRatings of PE lesson activities\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 113px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eImplementation\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 312px;\\\"\\u003e\\n \\u003cp\\u003eThe extent, likelihood, and manner in which the program can be fully implemented as planned.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 236px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 265px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003eNumber of PE lessons delivered\\u003c/li\\u003e\\n \\u003cli\\u003eNumber of energiser breaks delivered\\u003c/li\\u003e\\n \\u003cli\\u003eNumber of home tasks assigned and completed\\u003c/li\\u003e\\n \\u003cli\\u003ePerceived ease of implementation\\u003c/li\\u003e\\n \\u003cli\\u003eConfidence with program delivery\\u003c/li\\u003e\\n \\u003cli\\u003eDifficulty motivating students\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 113px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eAdaptation\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 312px;\\\"\\u003e\\n \\u003cp\\u003eThe extent to which an existing program can be adapted to fit the needs of different populations.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 236px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 265px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003ePerceived adaptability of program\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 113px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003ePracticality\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 312px;\\\"\\u003e\\n \\u003cp\\u003eThe extent to which the program can be delivered using existing resources or with limited resources, and without outside intervention.\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 236px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd valign=\\\"top\\\" style=\\\"width: 265px;\\\"\\u003e\\n \\u003cul\\u003e\\n \\u003cli\\u003eUse of program resources\\u003c/li\\u003e\\n \\u003cli\\u003ePerceived quality of program resources\\u003c/li\\u003e\\n \\u003cli\\u003eSuitability of school facilities\\u003c/li\\u003e\\n \\u003c/ul\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 3.\\u003c/strong\\u003e Summary of feasibility evaluation for teachers (\\u003cem\\u003eN\\u003c/em\\u003e = 2)\\u003c/p\\u003e\\n\\u003ctable border=\\\"0\\\" cellspacing=\\\"0\\\" cellpadding=\\\"0\\\" width=\\\"614\\\"\\u003e\\n \\u003ctbody\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eFeasibility domain\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eSurvey items/measures\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eResult\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eAcceptability\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eOverall satisfaction with program (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eWould recommend program to others (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eIntend to sustain delivery, \\u003cem\\u003en\\u003c/em\\u003e (%) \\u0026lsquo;yes\\u0026rsquo;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e2 (100)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eLikely to deliver PE lessons again (/11)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e11.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eLikely to deliver energiser breaks again (/11)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e11.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eLikely to deliver home tasks again (/11)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e9.5 (2.1)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003ePerceived benefits to students\\u0026rsquo; physical health (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003ePerceived benefits to students\\u0026rsquo; mental health (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eOther teachers supportive of program (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eSchool executive supportive of program (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eMean rating for \\u003cem\\u003eStart Strong\\u003c/em\\u003e lesson activities (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e4.9 (0.3)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eMean rating for \\u003cem\\u003eMain Muscles\\u003c/em\\u003e lesson activities (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e4.5 (0.5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eMean rating for \\u003cem\\u003eMuscle-Up\\u0026nbsp;\\u003c/em\\u003elesson activities (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e4.4 (0.7)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eImplementation\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eNumber of PE lessons delivered overall\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e6.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eNumber of energiser breaks delivered per week\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.5 (2.1)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eNumber of home tasks assigned overall\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (1.4)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eNumber of home tasks students completed\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e2.5 (0.7)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003ePerceived ease of implementation (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eConfidence with program delivery (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eDifficult finding time to implement (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e1.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eDifficult to motivate students for PE lessons (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e1.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eDifficult to motivate students for energisers (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e1.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eDifficult to motivate students for home tasks (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e3.0 (1.4)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eAdaptation\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003ePerceived adaptability of program (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003ePracticality\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003ePerceived quality of program resources (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003ePerceived suitability of school facilities (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eUsed program resources for most PE lessons (/5)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eUsed \\u003cem\\u003eManagers\\u003c/em\\u003e wall chart, \\u003cem\\u003en\\u003c/em\\u003e (%) \\u0026lsquo;yes\\u0026rsquo;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e1 (50.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 141px;\\\"\\u003e\\n \\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 350px;\\\"\\u003e\\n \\u003cp\\u003eUsed \\u003cem\\u003eMotivators\\u003c/em\\u003e wall chart, \\u003cem\\u003en\\u003c/em\\u003e (%) \\u0026lsquo;yes\\u0026rsquo;\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 123px;\\\"\\u003e\\n \\u003cp\\u003e2 (100)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003csup\\u003ea\\u0026nbsp;\\u003c/sup\\u003e\\u003c/strong\\u003eValues are mean and standard deviation unless otherwise specified.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTable 4.\\u0026nbsp;\\u003c/strong\\u003eChange in student outcomes\\u003c/p\\u003e\\n\\u003ctable border=\\\"1\\\" cellspacing=\\\"0\\\" cellpadding=\\\"0\\\" width=\\\"822\\\"\\u003e\\n \\u003ctbody\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 217px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eOutcomes\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 94px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003eN\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eBaseline\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eMean (SD)\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003ePost-test\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eMean (SD)\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 142px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003eMean change\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;(95%CI)\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003e\\u003cstrong\\u003e\\u003cem\\u003ed\\u003c/em\\u003e\\u003c/strong\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 217px;\\\"\\u003e\\n \\u003cp\\u003ePerceived strength, units\\u003csup\\u003ea\\u003c/sup\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 94px;\\\"\\u003e\\n \\u003cp\\u003e25\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e5.0 (0.9)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e5.1 (0.9)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 142px;\\\"\\u003e\\n \\u003cp\\u003e0.1 (-0.1, 0.4)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003e0.22\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 217px;\\\"\\u003e\\n \\u003cp\\u003ePush-ups, repetitions\\u003csup\\u003eb\\u003c/sup\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 94px;\\\"\\u003e\\n \\u003cp\\u003e25\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e5.5 (6.7)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e7.7 (7.8)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 142px;\\\"\\u003e\\n \\u003cp\\u003e2.2 (0.7, 3.8)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003e0.61\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003ctr\\u003e\\n \\u003ctd style=\\\"width: 217px;\\\"\\u003e\\n \\u003cp\\u003eStanding long jump, cm\\u003csup\\u003ec\\u003c/sup\\u003e\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 94px;\\\"\\u003e\\n \\u003cp\\u003e26\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e129.9 (17.8)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 132px;\\\"\\u003e\\n \\u003cp\\u003e128.5 (17.0)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 142px;\\\"\\u003e\\n \\u003cp\\u003e-1.4 (-7.4, 4.7)\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003ctd style=\\\"width: 104px;\\\"\\u003e\\n \\u003cp\\u003e-0.09\\u003c/p\\u003e\\n \\u003c/td\\u003e\\n \\u003c/tr\\u003e\\n \\u003c/tbody\\u003e\\n\\u003c/table\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eNote.\\u0026nbsp;\\u003c/strong\\u003eCI, confidence intervals;\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eMSA, muscle-strengthening activity; SD, standard deviation.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003csup\\u003ea\\u0026nbsp;\\u003c/sup\\u003e\\u003c/strong\\u003eFive students did not provide complete data for perceived strength.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003csup\\u003eb\\u0026nbsp;\\u003c/sup\\u003e\\u003c/strong\\u003eThree students were absent and two students had a precluding injury for the push-up test.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u003csup\\u003ec\\u0026nbsp;\\u003c/sup\\u003e\\u003c/strong\\u003eThree students were absent and one had a precluding injury for the standing long jump test.\\u003cstrong\\u003e\\u003c/strong\\u003e\\u0026nbsp; \\u0026nbsp; \\u0026nbsp; \\u0026nbsp; \\u0026nbsp; \\u0026nbsp; \\u0026nbsp; \\u0026nbsp;\\u0026nbsp;\\u003c/p\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":true,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":true,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"pilot-and-feasibility-studies\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"pafs\",\"sideBox\":\"Learn more about [Pilot and Feasibility Studies](http://pilotfeasibilitystudies.biomedcentral.com/)\",\"snPcode\":\"\",\"submissionUrl\":\"https://www.editorialmanager.com/PAFS/default.aspx\",\"title\":\"Pilot and Feasibility Studies\",\"twitterHandle\":\"@MedicalEvidence\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"BMC/SO AJ\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true},\"keywords\":\"strength, physical education, teacher, intervention, resistance training\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-7116548/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-7116548/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003e\\u003cstrong\\u003eBackground: \\u003c/strong\\u003eMuscle-strengthening activity (MSA) is beneficial for school-aged children, but most school-based MSA interventions have been delivered by external specialists or research staff, limiting scalability. We aimed to assess the feasibility of a teacher-delivered MSA intervention for children in advance of a future efficacy trial.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eMethods: \\u003c/strong\\u003eWe conducted a single-group feasibility trial with two Stage 2 (i.e., grade 3-4) classes from one primary school in New South Wales, Australia. The 6-week \\u003cem\\u003eMuscle Movers \\u003c/em\\u003eintervention included: (i) enhanced PE lessons focused on foundational MSA skills (1 x 45 mins/week), (ii) classroom energiser breaks (2 x 5 mins/week), and (iii) active homework tasks (1 x 10 mins/week). We assessed acceptability, implementation, adaptation, and practicality using survey and interview methods. We also assessed pre-post change in children’s perceived strength, upper-body muscular endurance, and lower-body muscular power. Data were analysed in SPSS (V.25) using descriptive statistics and paired-samples \\u003cem\\u003et\\u003c/em\\u003e-tests, with Cohen’s \\u003cem\\u003ed \\u003c/em\\u003eas a measure of effect size.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eResults: \\u003c/strong\\u003eTwo female teachers (31 and 59 years) and 30 students (mean [SD] = 9.8 [0.6] years; 40% female) were enrolled. Acceptability was high for teachers (mean [SD] = 5.0[0.0] out of 5) and students (mean [SD] = 4.1[1.0] out of 5). Teachers implemented all PE lessons, and more than double the intended energiser breaks (mean [SD] = 5.5[2.1] per week). Conversely, homework task assignment (mean [SD] = 5.0 [1.4]) and completion (mean [SD] = 2.5[0.7]) were lower than intended. Teachers reported high confidence to deliver the program and viewed it as practical and adaptable. We found a moderate increase in children’s push-up performance (mean [95%CI] = 2.2 repetitions [0.7 to 3.8]; \\u003cem\\u003ed\\u003c/em\\u003e = 0.61), but no meaningful changes in perceived strength (mean [95%CI] = 0.1 units [-0.1 to 0.4]; \\u003cem\\u003ed\\u003c/em\\u003e = 0.22) or standing long jump (mean [95%CI] = -1.4 cm [-7.4 to 4.7]; \\u003cem\\u003ed\\u003c/em\\u003e = -0.09).\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eConclusions: \\u003c/strong\\u003eMuscle Movers was feasible for classroom teachers to implement in a primary school setting. The observed improvement in students’ upper-body muscular endurance should be confirmed using an appropriately powered randomised controlled trial.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eTrial registration: \\u003c/strong\\u003eRetrospectively registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12625000703404)\\u003c/p\\u003e\",\"manuscriptTitle\":\"Feasibility of ‘Muscle Movers’: A teacher-delivered program to support children’s participation in muscle-strengthening physical activity\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-09-08 10:39:13\",\"doi\":\"10.21203/rs.3.rs-7116548/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"reviewerAgreed\",\"content\":\"\",\"date\":\"2025-08-31T23:54:32+00:00\",\"index\":0,\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2025-08-29T02:26:16+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorAssigned\",\"content\":\"\",\"date\":\"2025-08-11T05:32:42+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Pilot and Feasibility Studies\",\"date\":\"2025-08-04T04:48:21+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"decision\",\"content\":\"Major revision\",\"date\":\"2025-07-14T09:10:26+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"pilot-and-feasibility-studies\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"pafs\",\"sideBox\":\"Learn more about [Pilot and Feasibility Studies](http://pilotfeasibilitystudies.biomedcentral.com/)\",\"snPcode\":\"\",\"submissionUrl\":\"https://www.editorialmanager.com/PAFS/default.aspx\",\"title\":\"Pilot and Feasibility Studies\",\"twitterHandle\":\"@MedicalEvidence\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"em\",\"reportingPortfolio\":\"BMC/SO AJ\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"db6eb1b5-088b-4007-95fa-313870538937\",\"owner\":[],\"postedDate\":\"September 8th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"published-in-journal\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-12-22T16:11:36+00:00\",\"versionOfRecord\":{\"articleIdentity\":\"rs-7116548\",\"link\":\"https://doi.org/10.1186/s40814-025-01751-0\",\"journal\":{\"identity\":\"pilot-and-feasibility-studies\",\"isVorOnly\":false,\"title\":\"Pilot and Feasibility Studies\"},\"publishedOn\":\"2025-12-16 15:58:16\",\"publishedOnDateReadable\":\"December 16th, 2025\"},\"versionCreatedAt\":\"2025-09-08 10:39:13\",\"video\":\"\",\"vorDoi\":\"10.1186/s40814-025-01751-0\",\"vorDoiUrl\":\"https://doi.org/10.1186/s40814-025-01751-0\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-7116548\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-7116548\",\"identity\":\"rs-7116548\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}