Impact of Varying Durations of One-Week Mild Hyperbaric Oxygen Therapy on Fatigue Recovery After Endurance Exercise in Rats

Impact of Varying Durations of One-Week Mild Hyperbaric Oxygen Therapy on Fatigue Recovery After Endurance Exercise in Rats | 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 Impact of Varying Durations of One-Week Mild Hyperbaric Oxygen Therapy on Fatigue Recovery After Endurance Exercise in Rats Chaoyi Qu, Minxiao Xu, Santiago Lorenzo, Peng Huang, Zhijian Rao, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5440032/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Fatigue is a common physiological phenomenon in sports. There are reports describing the beneficial effects of exposure to Mild Hyperbaric Oxygen Therapy (MHOT) on metabolic diseases. However, the effects of MHOT on exercise-induced fatigue have not been fully investigated. Therefore, this study aimed to analyze the effects of different MHOT intervention time protocols (30 min and 60 min) on one week of endurance exercise-induced fatigue in rats. Methods A total of 32 male Wistar rats (aged 6 weeks) were randomly assigned into to control group (C), exercise group (E), MHOT for 30min after exercise group (EMHOT30min) and MHOT for 60min after exercise group (EMHOT60min), with 8 rats in each group. In the exercise group, rats underwent treadmill exercise sessions lasting 90 minutes each day, conducted six times a week, once a day for one week. These exercise sessions were tailored based on the measurement range of maximum oxygen uptake. After each exercise session, the E group underwent a routine quiet rest (1 ATA, 20.9% oxygen). Conversely, the EMHOT30min and EMHOT60min groups were exposed to an MHOT environment for 30 minutes and 60 minutes, respectively (1.25ATA, 26%-28% oxygen concentration). Baseline measurements and aerobic exercise capacity tests were conducted before and after the one-week intervention period. At the end of the intervention, a complete blood count and biochemical analyses of enzyme activity were also performed. Results The results show that the MHOT intervention groups significantly increased aerobic exercise capacity and promoted the recovery of blood oxygen content. Moreover, the EMHOT60min group was better than the EMHOT30min group ( P < .05). Muscle damage and metabolite levels induced by one week of endurance exercise were significantly reduced in the MHOT intervention groups, with no significant difference observed between the two MHOT groups ( P > .05). The MHOT intervention also significantly enhanced antioxidant levels, compared with EMHOT30min group, the effect of EMHOT60min group is more obvious ( P < .05). Conclusions These data suggest that both the 30-minute and 60-minute MHOT interventions effectively facilitated the reduction of fatigue in rats after one week endurance exercise. Moreover, the 60-minute MHOT intervention demonstrated a superior effect on aerobic exercise capacity and antioxidant capacity. This enhanced effect of the 60-minute protocol might be attributed to the cumulative time-response relationship inherent in MHOT intervention time protocol. Fatigue Mild hyperbaric oxygen therapy Recovery Rats Intervention time Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Physiological and psychological demands during training and competition generate fatigue and can reduce an athlete´s sport-specific performance [ 1 ] . A wide range of recovery modalities are now used as integral parts of the training and competition programs of elite athletes to help attenuate fatigue and enhance recovery [ 2 ] . As a World Anti-doping Agency (WADA) approved treatment, oxygen therapy has been used to improve exercise performance in sports [ 3 ] . Hyperoxia supplementation influences the cardiorespiratory, nervous, and endocrine systems, as well as energy metabolism, potentially leading to improvements in both performance and recovery [ 3 ] . Additionally, Hyperbaric Oxygen Therapy (HBOT) is an adjunct therapy for athletes to enhance recovery, minimize post-exercise muscle damage and swelling, and improve tissue remodeling following muscle injury [ 4 ] . On the other hand, it has been shown that hyperoxia and HBOT treatments may lead to potential side effects such as barotrauma, oxygen toxicity, and the risk of increased oxidative stress with prolonged hyperoxia exposure [ 3 ] . In fact, there is ongoing controversy regarding the effectiveness of HBOT versus hyperoxia therapy in enhancing sports performance and recovery, with studies showing inconclusive results [ 5 , 6 ] . Mild Hyperbaric Oxygen Therapy (MHOT), characterized by exposure to slightly elevated atmospheric pressure 1.24–1.29 atmosphere absolute (ATA) and enriched oxygen levels (25–40% oxygen), emerges as a promising alternative to mitigate exercise-induced fatigue [ 7 , 8 ] . By avoiding the pitfalls of barotrauma and excessive reactive oxygen species production, MHOT is poised to offer therapeutic advantages in metabolic regulation and disease management. Its role in combating muscle atrophy and enhancing cellular metabolism makes it a compelling option for sports recovery [ 7 , 8 ] . Recent research has explored the application of MHOT in sports to assess its impact on recovery. Findings suggest that MHOT shows promise as an effective method for improving mood states following high-intensity training [ 9 ] . Additionally, studies suggest that 1.3 ATA oxygen therapy is an effective strategy for enhancing cardiac parasympathetic reactivation, which may contribute to improved subsequent sports performance [ 10 ] . There is a lack of research on how different durations of MHOT affect post-exercise recovery. This gap in knowledge has hindered both research and practical applications of MHOT in sports science. Additionally, there aren't enough animal studies exploring how MHOT specifically impacts fatigue recovery after exercise. To address these issues, we conducted a study on rats to investigate how different durations of acute MHOT interventions affect fatigue mitigation after endurance exercise. Our research was based on existing studies of hyperoxia, HBOT, and MHOT in relation to exercise, as well as the equipment available to us and practical considerations. [ 5 – 9 ] . We hypothesized that MHOT will improve fatigue recovery in rats after endurance exercise compared to a standard air environment (1 ATA, 20.9% oxygen), and we expect that different durations of MHOT treatment will yield varying levels of effectiveness. This study aims to investigate how MHOT affects fatigue recovery following one week of endurance exercise and to identify the most effective treatment duration. Ultimately, our findings are intended to provide valuable insights for future research and practical applications of MHOT in sports science and exercise recovery. Methods Animals and Experimental design Thirty-two male Wistar rats (age: 6 weeks, weight: 190 ~ 210 g) were provided by the Beijing Vital River Laboratory Animal Technology Co., Ltd. All rats were raised in ventilated caging system separately under a 12:12 h light-dark cycle (23 ± 2.0℃ and 45%-55% humidity). The rats were divided into four groups of eight at random: control group (C), exercise group (E), post exercise MHOT 30min group (EMHOT30min) and post exercise MHOT 60min group (EMHOT60min). The C group underwent normal feeding without any exercise or recovery intervention. After one week of acclimatization with feeding and watering, all rats in the E, EMHOT30min, and EMHOT60min groups were trained for 1 week on the treadmill (10 m/min speed, 0° gradient, 10 minutes) to familiarize them with the exercise regimen. Following treadmill adaptation, these groups underwent a 1-week aerobic treadmill training program, consisting of six sessions with 90 minutes of treadmill running per day (60%-65% maximal oxygen uptake (V̇O 2 max), 65%-70% V̇O 2 max, and 70%-75% V̇O 2 max for 30 minutes each, at a 0° gradient). After completing the exercise protocol, each group received different interventions. The E group experienced natural environment recovery (1 ATA, 20.9% oxygen concentration), while the EMHOT30min and EMHOT60min groups were exposed to MHOT conditions (1.25 ATA, 26%-28% oxygen concentration) for 30 minutes and 60 minutes, respectively. During the pre-exercise baseline and after the 1-week intervention the E, EMHOT30min and EMHOT60min groups underwent an aerobic exercise capacity test. Following, the rats were anesthetized, and blood was collected to assess the complete blood count and biochemical analyses of enzyme activity. The study design is shown in Fig. 1 . All the procedures were approved by the Animal Ethical Committee of the China Institute of Sports Science in accordance with the guidelines of experimental animal use. Exercise protocol Rats in the E, EMHOT30min and EMHOT60min groups underwent aerobic treadmill (DSPT-202, China) training for 90 min every day for 1 week (six times). The aerobic treadmill training protocol consisted of a 5-minute warm-up followed by three consecutive sessions of moderate aerobic exercise. Each session was performed at increasing intensities of 60%-65% V̇O 2 max, 65%-70% V̇O 2 max, and 70%-75% V̇O 2 max, respectively, with each period lasting 30 minutes [11, 12 ] . The total exercise duration was 90 minutes, encompassing three consecutive periods [13−15] . The protocol did not include intermittent rest breaks during any of the treadmill exercises. Finally, the protocol concluded with a 5-minute cool-down period. This exercise protocol was notably time-consuming and physically demanding, leading to exhaustion among the rats. Treatment The E, EMHOT30min, and EMHOT60min groups were exposed to different recovery modalities during the experiment. The rats in the E group were placed in a rearing cage within their natural environment routine quiet rest conditions (1 ATA, 20.9% oxygen, temperature ranging from 20 to 26°C) after each exercise session. All treatments procedures were designed based on prior published studies on HBOT and sports, MHOT and sports [ 6 – 9 , 16 ] . The EMHOT30min and EMHOT60min groups were subjected to mild hyperbaric oxygen therapy using a chamber (Beijing Chuang Xin Kaida Technology Co., Ltd). This chamber featured an oxygen standard soft cabin (210 cm in length, 72 cm in width), allowing the rats to lie down comfortably in a rearing cage, and a compressor control box (56 cm in length, 50 cm in width, 99 cm in height) that housed an oxygen concentrator and an air compressor. The atmospheric pressure and oxygen concentration were precisely regulated by a computer-assisted system within the control box. The device is configured with preset oxygen pressure and concentration settings, which cannot be adjusted during the intervention. In the EMHOT30min group, the MHOT intervention was administered post-exercise for 30 minutes at 1.25 ATA with 26%-28% oxygen concentration, based on the device's preset configuration. In the EMHOT60min group, the MHOT intervention lasted for 60 minutes under the same pressure and oxygen concentration conditions. These parameters were consistent with those recommended by MHOT-related research [ 7 – 9 ] . The chamber conditions were maintained at a temperature of 22 ± 8°C with a relative humidity of 40–60%. Before entering the oxygen chamber, rats were provided with food and water as usual, and their performance and condition were closely monitored throughout the intervention period. Aerobic exercise capacity test Rats in the E, EMHOT30min and EMHOT60min groups underwent V̇O 2 max test to assess aerobic exercise capacity. This test was conducted both at baseline and following the 1-week intervention. V̇O 2 max was measured to determine the exercise treadmill intensity (running speed) and was evaluated with the Columbus Oxymax Lab Animal Monitoring System (Columbus, USA). Experimental parameters included oxygen uptake (V̇O 2 ) and respiratory exchange ratio (RER), running distance, speed, and time were assessed using a Columbus Oxymax Lab Animal Monitoring System and an animal treadmill chamber. A gas analyzer was calibrated with ambient air and a reference gas in a room with stable temperature and humidity. Before starting the test, the body mass of the rats was measured. The test protocol began with a 2-minute warm-up period at a speed of 12 m/min. After 3 minutes, the treadmill speed was elevated to 15 m/min. Subsequently, the treadmill speed was increased by 5 m/min every 3 minutes, while maintaining the treadmill slope at 0°, until the rats reached volitional exhaustion [17] . We employed several criteria to ensure the V̇O 2 max and maximum aerobic exercise capacity were reached during the rat tests. These criteria included: observing that the increase in V̇O 2 was less than 5% despite the increased workload, noting RER above 1.00, and identifying signs of exhaustion such as unwillingness to run, feeble kicking of hind legs, and mental sluggishness. As soon as any two of these criteria were met, we terminated the test and recorded the corresponding test values [11,1 8 ] . Sample collection Before euthanasia, the rat was fasted for 12 hours to standardize metabolic conditions. 24 hours After aerobic exercise capacity test, Animals were anaesthetized prior to euthanasia to ensure they were unconscious and experienced minimal discomfort. All rats were anesthetized with an intraperitoneal injection, 10% chloral hydrate, according to the ratio of 0.35 ~ 0.4 ml/100 g of weight, the depth of anaesthesia was controlled by the observation of pinna and withdrawal reflexes. Then blood was collected through the abdominal aorta. After blood sample collection rat were euthanized immediately through cervical dislocation. Complete blood count A total of 1.5 ml of blood was extracted from the abdominal aorta of the rats and treated with EDTA to prevent coagulation. The collected blood samples underwent analysis using the Mindray BC-5000 Automatic Hematology Analyzer (Mindray Bio-Medical Electronics Co., Ltd, Shenzhen, China) to assess various parameters. Complete blood count detection indicators include Red Blood Cell (RBC); Hemoglobin (HGB); Hematocrit (HCT); Mean Corpuscular Volume (MCV); Mean Corpuscular Hemoglobin (MCH); Mean Corpuscular Hemoglobin Concentration (MCHC); RBC Distribution Width (RDW); Platelet Count (PLT); Mean Platelet Volume (MPV); White Blood Cell (WBC); Neutrophil Count (NEUT-abs); lymphocytes Count (LYMPH-abs); Monocytes Count (MONO-abs); Eosinophils Count (EOS-abs); Basophils Count (BASO-abs); Neutrophil percentage (NEUT%); lymphocytes percentage (LYMPH%); Monocytes percentage (MONO%); Eosinophils percentage (EOS%); Basophils percentage (BASO%). Biochemical analyses of serum enzyme activity A total of 4.5 mL of blood was drawn from the rats in each group and collected into serum separator tubes. After centrifugation at 3500 revolutions per minute at 4°C for 20 minutes, serum samples were obtained. These samples were divided into multiple aliquots and stored at -80°C until further analysis. The levels of serum Creatine Kinase (CK) and Lactate Dehydrogenase (LDH) were assessed using VITROS Chemistry CK and LDH DT slides (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). Serum levels of Lactate (LA) and Catalase (CAT) were determined using commercially available kits according to the manufacturers’ instructions (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). The assessment of serum Malondialdehyde (MDA) levels was conducted following the Yagi method [ 19 , 20 ] . This method involves the measurement of Thiobarbituric acid (TBA) reactive substances, which serve as reaction products. The quantification of these substances was performed at a wavelength of 532 nm using spectrophotometry. Superoxide dismutase (SOD) serum level was measured using the commercially available enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer’s instructions (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). The assay detection limit of SOD was 3 U/ml, with intra-assay and inter-assay coefficients of variation (CV) of 9% and 15%, respectively. The determination of Total Antioxidant Capacity (TAOC) in serum was conducted through the Ferric ion reducing antioxidant power (FRAP) method. Optical density measurements were recorded at 593 nm using an enzyme-linked analyzer (Multiskan Asc, Thermo, USA). Statistical analysis All measurement results data are presented as the mean ± standard deviation (SD). Statistical analyses were performed using SPSS (version 22.0, IBM SPSS Statistics, Chicago, IL). Statistical significance was defined as P < 0.05 . The Kolmogorov–Smirnov test was applied for testing normal distribution of data. A One-way Analysis of Variance (ANOVA) was employed to compare the complete blood count and serum enzyme activity measurements among the four groups. Post-hoc multiple comparisons were conducted using the Least Significant Difference (LSD) test or Dunnett’s test to further analyze and determine specific differences between the individual groups. For the comparison of aerobic exercise capacity test indicators within the same group before and after intervention, a matched samples t -test was utilized. Additionally, to compare these indicators between different groups, a one-way ANOVA was employed. A Kruskal–Wallis test was used for non-normally distributed data. Furthermore, effect size estimates (Cohen’s d) were calculated to further assess efficacy. The data were interpreted with effect sizes categorized as small ( d = 0.2–0.5), medium ( d = 0.5–0.8), or large ( d ≥ 0.8) [ 18 , 21 ] . Results Effects of different interventions on aerobic exercise capacity Figure 2 illustrates the effects of the different interventions on aerobic exercise capacity in rats. Post-intervention running distance, running speed, and running time were increased compared with pre-intervention in the E group (distance: P < 0.05, ES = 0.44; speed: P < 0.05, ES = 0.52; time: P < 0.05, ES = 0.45), the EMHOT30min group (distance: P < 0.01, ES = 0.88; speed: P < 0.01, ES = 0.83; time: P < 0.01, ES = 0.83), and the EMHOT60min group (distance: P < 0.01, ES = 0.79; speed: P < 0.01, ES = 0.84; time: P < 0.05, ES = 0.72). Post-intervention, the EMHOT60min group showed a significant increase in running distance and speed compared to the E group (distance: P < 0.01, ES = 0.63; speed: P < 0.05, ES = 0.56) and the EMHOT30min group (distance: P < 0.05, ES = 0.51; speed: P < 0.05, ES = 0.50). Additionally, post-intervention running time in the EMHOT60min group was significantly higher compared to the E group ( P < 0.05, ES = 0.62). Finally, post-intervention V̇O 2 max was significantly increased compared to pre-intervention in the EMHOT30min group ( P < 0.01, ES = 0.45) and the EMHOT60min group ( P < 0.01, ES = 0.60). The EMHOT60min group also showed a significant increase in V̇O 2 max compared to the E group ( P < 0.01, ES = 0.61). Effects of different interventions on complete blood count The results from Table 1 highlight various changes in blood parameters among the groups. Specifically, the EMHOT60min group showed a statistically significant increase in HGB levels post-intervention compared to the E group ( P < 0.05, ES = 0.85). Regarding MCH levels, the EMHOT30min group had significantly higher MCH levels compared to the E group ( P < 0.05, ES = 0.52). The EMHOT60min group exhibited significant increases in MCH levels compared to both the E group ( P < 0.05, ES = 0.88) and the EMHOT30min group ( P < 0.05, ES = 0.60). Concerning MCHC levels, the EMHOT30min group showed significant increases compared to the E group ( P < 0.05, ES = 0.52). The EMHOT60min group had significantly elevated MCHC levels compared to the C group ( P < 0.05, ES = 0.65), the E group ( P < 0.05, ES = 0.89), and the EMHOT30min group ( P < 0.05, ES = 0.73) No significant differences were observed in other complete blood count parameters among the four groups. Table 1 Post-intervention effects on complete blood count Complete Blood Count C group(n = 6) E group(n = 6) EMHOT30min group(n = 6) EMHOT60min group(n = 6) RBC(x10 6 /uL) 2.10 ± 0.67 2.21 ± 0.36 2.11 ± 0.45 2.01 ± 0.50 HGB (g/L) 136 ± 32.24 # 109.66 ± 8.77 127.83 ± 15.17 134.66 ± 6.56 # HCT (%) 35.08 ± 4.96 31.58 ± 3.21 34.55 ± 4.73 36.05 ± 2.27 MCV(fL) 58.06 ± 1.22 58.56 ± 2.43 58.46 ± 0.55 59.13 ± 0.84 MCH(Pg) 22.68 ± 0.57 #△ 21.23 ± 0.51 21.96 ± 0.66 # 22.71 ± 0.23 #△ MCHC(g/L) 371.33 ± 2.80 # 363.16 ± 3.71 368.16 ± 4.44 # 375.83 ± 2.31 *#△ RDW (%) 11.95 ± 0.24 12.03 ± 0.58 12.43 ± 0.60 12.08 ± 0.29 PLT (x10 3 /UL) 1113.33 ± 182.66 985.66 ± 316.49 1027.16 ± 191.35 1114.50 ± 283.02 MPV (fL) 6.63 ± 0.30 6.6 ± 0.31 6.83 ± 0.23 6.85 ± 0.33 WBC (x10 3 /UL) 2.10 ± 0.67 2.41 ± 0.36 2.11 ± 0.45 2.01 ± 0.50 NEUT-abs (x10 3 /UL) 0.51 ± 0.14 0.58 ± 0.37 0.42 ± 0.21 0.45 ± 0.14 LYMPH-abs (x10 3 /UL) 1.58 ± 0.39 1.29 ± 0.53 1.35 ± 0.67 1.04 ± 0.54 MONO-abs (x10 3 /UL) 0.14 ± 0.04 0.14 ± 0.03 0.15 ± 0.05 0.12 ± 0.07 EOS-abs (x10 3 /UL) 0.02 ± 0.008 0.01 ± 0.005 0.02 ± 0.020 0.01 ± 0.122 BASO-abs (x10 3 /UL) 0.01 ± 0.012 0.01 ± 0.011 0.008 ± 0.009 0.006 ± 0.008 NEUT% (%) 22.2 ± 2.83 27.21 ± 12.63 21.4 ± 1.39 24.98 ± 3.03 LYMPH% (%) 69.71 ± 4.26 68.26 ± 13.10 69.03 ± 1.60 66.9 ± 1.81 MONO% (%) 6.30 ± 1.29 7.7 ± 2.33 7.93 ± 1.72 8.01 ± 2.24 EOS% (%) 1.11 ± 0.33 1.01 ± 0.14 1.2 ± 0.22 1.31 ± 0.77 BASO%(%) 0.66 ± 0.37 0.80 ± 0.37 0.60 ± 0.16 0.45 ± 0.32 C: Control group; E: Exercise group; EMHOT30min: post exercise MHOT 30min group; EMHOT60min: post exercise MHOT 60min group; * significantly different from C group ( P < 0.05 ); # significantly different from E group ( P < 0.05 ); △ significantly different from EMHOT30min group ( P < 0.05 ); Effects of different interventions on serum enzyme activity Figure 3 illustrates the changes in CK, LDH, and LA levels. Post-intervention, groups C ( P < 0.01, ES = 0.79), EMHOT30min ( P < 0.01, ES = 0.69), and EMHOT60min ( P < 0.01, ES = 0.86) exhibited statistically significant reductions in CK levels compared to group E. In contrast, LDH levels showed no significant differences among the four groups. For LA levels, groups C ( P < 0.01, ES = 0.67), EMHOT30min ( P < 0.01, ES = 0.77), and EMHOT60min ( P < 0.01, ES = 0.79) also demonstrated significant reductions compared to group E. At the post-intervention assessment, noticeable differences in SOD and TAOC levels were observed among the groups. The EMHOT30min group displayed statistically significant higher SOD and TAOC levels compared to both the C group ( P < 0.01, ES = 0.79 ), ( P < 0.05, ES = 0.52 ) and the E group ( P < 0.01, ES = 0.84 ), ( P < 0.01, ES = 0.68 ). Similarly, the EMHOT60min group exhibited a statistically significant increase in SOD and TAOC levels at the post-intervention time point compared to both the C group ( P < 0.01, ES = 0.81 ), ( P < 0.01, ES = 0.69 ) and the E group ( P < 0.01, ES = 0.86 ), ( P < 0.01, ES = 0.79 ). Figure 4 reveals distinct findings in MDA levels, with the EMHOT30min group showing a significant reduction compared to the E group ( P < 0.01, ES = 0.67 ) and the EMHOT60min group demonstrating statistically significant decreases compared to both the C group ( P < 0.01, ES = 0.60 ) and the E group ( P < 0.01, ES = 0.74 ). Figure 4 shows variations in CAT levels, where the EMHOT30min group had a statistically significantly higher CAT levels compared to the C group ( P < 0.05, ES = 0.51 ), and the EMHOT60min group exhibited statistically significant increases compared to both the C group ( P < 0.05, ES = 0.56 ) and the E group ( P < 0.05, ES = 0.46 ). Discussion Fatigue model following one week of endurance exercise In the present study, exercise exhaustion was determined by specific criteria: the rats were unable to maintain the predetermined speed, their abdomens stayed in contact with the runway surface, and their hind legs showed signs of weakness. The rats were considered to have reached complete exhaustion after continuous exposure to sound, light, and mechanical stimulation, which eventually caused them to stop running [ 11 , 15 ] . After completing a series of six endurance exercise sessions, rats in the E, EMHOT30min, and EMHOT60min groups exhibited noticeable physical changes indicative of fatigue. These included slower reaction times, weaker kicking motions, and even instances where the rats assumed a supine position, all clear signs of exhaustion [ 11 , 17 ] . These observations suggest that the endurance exercise fatigue protocol used in this study successfully aligns with the established criteria for modeling exercise-induced fatigue in rats. Impact of MHOT on aerobic exercise capacity following one week of endurance exercise The results show the MHOT intervention (30min and 60min groups) significantly increased rats aerobic exercise capacity. Similar results have been observed in related protocols involving MHOT exposure in rats. For instance, running ability improved in rats exposed to MHOT, attributed to the enhanced oxidative capacity of the soleus and plantaris muscle fibers, along with an increase in the activity of their spinal motoneurons following MHOT intervention [ 22 ] . Another study highlighted that the combination of MHOT and training can improve aerobic exercise performance by enhancing oxidative and glycolytic capacities, as well as the expression of proteins involved in mitochondrial biogenesis in mice [ 23 ] . The study suggests that chronic intermittent MHOT exposure may aid in muscle damage recovery by upregulating heat shock protein 70 (HSP70), thereby improving muscular adaptation to exercise training [ 23 ] . Additionally, MHOT has been shown to have beneficial effects in both endurance and interval training, leading to improved exercise capacity in highly trained mice [ 24 ] . Research has also indicated that exposure to hyperbaric conditions, in combination with endurance training, can not only enhance oxidative and glycolytic capacities but also increase the protein levels of key factors such as mitochondrial transcription factor A, dynamin-related protein-1, and HSP70 [ 24 ] . A study suggested that MHOT does not enhance mitochondrial content acutely, but regular treatment might lead to upregulation of muscle mitochondrial biogenesis over time, increasing peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) mRNA levels [ 25 ] . In this study, we believe there is a possibility that MHOT may have a similar intervention effect, indicating its potential to enhance aerobic endurance by influencing key factors related to cellular energy production, mitochondrial function, and oxidative stress response. We propose that MHOT intervention could increase the dissolved oxygen content in plasma, improve the oxidative capacity of motor neurons, and thereby enhance their excitability during exercise. Additionally, MHOT may improve oxygen utilization and increase tolerance to aerobic exercise. In the aerobic exercise capacity test conducted in this study, the EMHOT60min group outperformed the EMHOT30min group. This difference in performance could be due to the longer exposure duration of 60 minutes in the MHOT intervention, suggesting a more sustained response within the body. Impact of MHOT on complete blood count following one week of endurance exercise The findings of this study indicate that MHOT intervention significantly enhanced the recovery of blood hemoglobin, with notable improvements in restoring blood oxygen levels. Specifically, the EMHOT60min group showed superior results compared to the EMHOT30min group, suggesting that a longer exposure of 60 minutes to MHOT more effectively restored blood oxygen content than the 30-minute exposure. This is consistent with other studies that have reported increases in peripheral oxygen saturation and blood flow following MHOT intervention [ 26 ] . The authors believe that exposure to MHOT may lead to an increase in blood flow and metabolism. This assertion is based on the understanding that MHOT has the capacity to augment the quantity of dissolved oxygen present in the plasma, consequently enhancing metabolic processes within cells and tissues [ 26 ] . Another study suggested that MHOT intervention significantly increases peripheral oxygen saturation, skin blood flow, and hemodynamics in finger capillaries in healthy individuals [ 16 ] . This effect is achieved by increasing the amount of oxygen bound to hemoglobin in red blood cells and elevating the levels of dissolved oxygen in the plasma [ 16 ] . Additionally, hyperoxia enhances micro vessel oxygenation through improved gas exchange, which helps maintain blood oxygen stability and supports the blood oxygen transport system [ 27 ] . Studies also indicate that MHOT enhances the body's oxygen-carrying capacity and accelerates oxygen diffusion throughout the body, improving micro vessel oxygenation and stabilizing the blood oxygen transport system [ 28 ] . Therefore, in this study, we believe that MHOT intervention facilitates a progression from stress compensation to adaptive feedback. The differing effects of 30-minute versus 60-minute MHOT interventions likely reflect the body's adaptive responses, suggesting that longer interventions may produce distinct responses and adaptations compared to shorter ones. Impact of MHOT on blood muscle damage and acid metabolites after one week of endurance exercise Results indicate that muscle damage and levels of metabolites such as CK and lactate (LA) were significantly reduced in the MHOT intervention groups, with no significant difference between the 30-minute and 60-minute exposure durations. Some studies have shown that lactate concentration during the 30-minute recovery period is notably lower in subjects receiving MHOT compared to controls after maximal exercise [ 29 ] . This aligns with our findings, suggesting that MHOT can alleviate peripheral fatigue and potentially enhance the clearance of fatigue-inducing substances generated by intense exercise [ 29 ] . Similarly, our published study found that repeated MHOT interventions reduced serum markers of muscle damage and metabolites after exercise-induced fatigue [ 8 ] . We believe MHOT improves oxygen diffusion from capillaries to adjacent cells, increases tissue and fluid oxygen content, supports tissue repair, and accelerates metabolite removal by raising dissolved oxygen levels. However, variations in CK, LDH, and LA levels might be influenced by factors such as the age of rats, their feeding environment, instrument calibration, test quality control, and reagents used. Therefore, further research with strictly controlled conditions is needed to fully understand the impact of MHOT intervention on these blood indicators. Impact of MHOT oxidative stress after one week of endurance exercise The results of serum oxidative stress indicators revealed that MHOT intervention significantly enhanced antioxidant levels, as evidenced by reduced MDA and increased SOD, CAT, and TAOC. These findings are consistent with previous reports indicating that MHOT can decrease muscle oxidative stress and improve antioxidant levels in rats with metabolic syndrome [ 30 ] . Additionally, MHOT has been shown to counteract the age-related decline in skeletal muscle oxidative capacity by boosting oxidative metabolism in cells and tissues [ 31 ] . Studies in dogs have also demonstrated increased glutathione peroxidase activity following MHOT intervention, suggesting that MHOT effectively modulates oxidative stress and stabilizes the organism's internal environment [ 32 ] . We believe that MHOT can effectively reduce free radical-induced tissue damage, lower lipid peroxidation, and maintain the oxidative-antioxidant balance, which benefits aerobic performance. Consequently, MHOT intervention may aid in eliminating free radicals, thereby preventing potential pathways to apoptosis induced by oxygen free radicals. Furthermore, MHOT intervention suggests that a longer adaptive period, such as a 60-minute exposure, may provide more extended adaptation effects and sustained tolerance. This longer duration likely facilitates a more pronounced adaptive response within the body and maintains tolerance to the intervention over a more extended period. Study limitations The study has several limitations that should be considered. The sample size was small and comprised only male rats. Additionally, blood indicators were not measured immediately after the intervention or at other time points, such as 1-hour post-exercise, which could reveal changes not captured in this study. Therefore, the results regarding blood indicators should be interpreted with caution. Furthermore, the study did not explore the underlying molecular pathways affected by MHOT intervention, leaving the mechanisms behind its fatigue-relieving effects unclear. The experimental model was also limited to investigating the effects of a 1-week MHOT treatment. Future research should focus on understanding the molecular pathways involved, include larger and more diverse samples, and examine the long-term effects of MHOT to provide a more comprehensive view of its mechanisms and potential for alleviating exercise fatigue in various contexts. Conclusions To our knowledge, this study is among the few that investigate and compare the effects of different MHOT intervention durations on fatigue following one week of endurance exercise in rats. The results indicate that both 30-minute and 60-minute MHOT interventions positively impacted the reduction of endurance exercise-induced fatigue. These interventions helped preserve aerobic exercise capacity and improve oxidative metabolism. Our findings suggest that MHOT's effectiveness in alleviating fatigue is likely due to enhanced aerobic metabolism, increased antioxidant capacity, and maintained internal environmental stability. The superior effectiveness of the 60-minute MHOT intervention compared to the 30-minute protocol may be attributed to its longer cumulative exposure time, which likely provides a more pronounced adaptive response. Therefore, a 60-minute MHOT intervention is recommended as a more effective protocol for promoting fatigue recovery after endurance exercise. Declarations Ethics approval and consent to participate All the procedures were approved by the Animal Ethical Committee of the China Institute of Sports Science (CISSLA-2020062801) in accordance with the guidelines of experimental animal use. Animals received humane care in compliance with the China Institute of Sports Science and the guide for the care and use. Consent for publication Not applicable. Competing interests The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. All authors declare that there are no conflicts of interest. Funding This work was supported by the General Research of Natural Science Foundation of Beijing (5212020) and the Doctoral Research Initiation Fund Project of Hebei Normal University (L2024 Author Contribution CY Qu, JX Zhao, MX Xu designed the experiments. P Huang and CY Qu, X Geng collected and analyzed the data. CY Qu, Santiago Lorenzo and ZJ Rao and JX Zhao edited the manuscript. All authors read and approved the submitted version. Acknowledgements This work was supported by the Laboratory of China Institute of Sport Science and Hebei Normal University Physical Education College. The authors thank all the participants for their efforts and help in this experiment. Data Availability The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. References Skorski S, Mujika I, Bosquet L, Meeusen R, Coutts AJ, Meyer T. The Temporal Relationship Between Exercise, Recovery Processes, and Changes in Performance. Int J Sports Physiol Perform. 2019;14(8):1015–21. Barnett A. Using recovery modalities between training sessions in elite athletes: does it help? Sports Med. 2006;36(9):781–96. Sperlich B, Zinner C, Hauser A, Holmberg HC, Wegrzyk J. The Impact of Hyperoxia on Human Performance and Recovery. Sports Med. 2017;47(3):429–38. Ishii Y, Deie M, Adachi N, Yasunaga Y, Sharman P, Miyanaga Y, Ochi M. Hyperbaric oxygen as an adjuvant for athletes. Sports Med. 2005;35(9):739–46. Mallette MM, Stewart DG, Cheung SS. The Effects of Hyperoxia on Sea-Level Exercise Performance, Training, and Recovery: A Meta-Analysis. Sports Med. 2018;48(1):153–75. Huang X, Wang R, Zhang Z, Wang G, Gao B. 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Effect of Hyperoxia on Critical Power and V˙O2 Kinetics during Upright Cycling. Med Sci Sports Exerc. 2020;52(5):1041–9. Kim S, Yukishita T, Lee K, Yokota S, Nakata K, Suzuki D, Kobayashi H. The Effect of Mild-Pressure Hyperbaric Therapy (Oasis O2) on Fatigue and Oxidative Stress. Health. 2011;3(7):432–6. Park SH, Park SJ, Shin MS, Kim CK. The effects of low-pressure hyperbaric oxygen treatment before and after maximal exercise on lactate concentration, heart rate recovery, and antioxidant capacity. J Exerc Rehabil. 2018;14(6):980–4. Takemura A, Ishihara A. Mild Hyperbaric Oxygen Inhibits Growth-related Decrease in Muscle Oxidative Capacity of Rats with Metabolic Syndrome. J Atheroscler Thromb. 2017;24(1):26–38. Nishizaka T, Nagatomo F, Fujino H, Nomura T, Sano T, Higuchi K, Takeda I, Ishihara A. Hyperbaric oxygen exposure reduces age-related decrease in oxidative capacity of the tibialis anterior muscle in mice. Enzyme Res. 2010;19(2010):824763. Ishibashi M, Hayashi A, Akiyoshi H, Ohashi F. The influences of hyperbaric oxygen therapy with a lower pressure and oxygen concentration than previous methods on physiological mechanisms in dogs. J Vet Med Sci. 2015;77(3):297–304. Additional Declarations No competing interests reported. Supplementary Files RatscompletedexerciseprotocolandMHOTinterventionprocedure.jpg Cite Share Download PDF Status: Posted Version 1 posted 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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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5440032","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":381009259,"identity":"48a799ea-f1e4-4eb4-b22f-f5eee78cc6ad","order_by":0,"name":"Chaoyi Qu","email":"","orcid":"","institution":"Hebei Normal University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Chaoyi","middleName":"","lastName":"Qu","suffix":""},{"id":381009264,"identity":"77229558-830c-4c45-8dad-6430360e4275","order_by":1,"name":"Minxiao Xu","email":"","orcid":"","institution":"China institute of sport science","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Minxiao","middleName":"","lastName":"Xu","suffix":""},{"id":381009265,"identity":"63095cb1-fffe-43a4-9827-cf360e9c8c9e","order_by":2,"name":"Santiago Lorenzo","email":"","orcid":"","institution":"Lake Erie College of Osteopathic Medicine-Bradenton","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Santiago","middleName":"","lastName":"Lorenzo","suffix":""},{"id":381009266,"identity":"9b71de60-ce36-44ce-8462-bc6be89dd893","order_by":3,"name":"Peng Huang","email":"","orcid":"","institution":"China institute of sport science","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Peng","middleName":"","lastName":"Huang","suffix":""},{"id":381009267,"identity":"bf07e72c-2766-4889-b774-c65536db9067","order_by":4,"name":"Zhijian Rao","email":"","orcid":"","institution":"China institute of sport science","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Zhijian","middleName":"","lastName":"Rao","suffix":""},{"id":381009268,"identity":"34344d79-a6bd-44ae-8b43-844e66acc4eb","order_by":5,"name":"Xue Geng","email":"","orcid":"","institution":"China institute of sport science","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Xue","middleName":"","lastName":"Geng","suffix":""},{"id":381009269,"identity":"fca148a7-6240-4b6f-9716-ec4031048c0f","order_by":6,"name":"Jiexiu Zhao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1UlEQVRIiWNgGAWjYDACCRA2YGBgY2A+wJBAoha2BBK0QACPAXHukp/d/PCBRYFNYp9EzscPD/7UMfDPbsCvhXHOMWMDCYM0YzaJ3M0SiW2HGSTuHMCvhVkiwUxCwuCwHFDLNobEhgMMBhIJ+LWwSaR/A2r5z8MmkfOMIQHoMIJaeCRyQLYcANqSw8aQwMZMWIuERE4x0C/Jxmw8z4xBfuGRuEFAi/yM9I2PJf7YJc5vT3748cefOjn+GQS0gACzBBKHh7B6IGD8QJSyUTAKRsEoGLEAAFpPN+3X+n8KAAAAAElFTkSuQmCC","orcid":"","institution":"China institute of sport science","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Jiexiu","middleName":"","lastName":"Zhao","suffix":""}],"badges":[],"createdAt":"2024-11-12 13:38:39","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5440032/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5440032/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":70366913,"identity":"b4fffdbf-49ce-4017-8d2e-292f69efb37f","added_by":"auto","created_at":"2024-12-02 14:21:21","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":179267,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eStudy design\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure1.Studydesign.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5440032/v1/17f6890e2bbe85ac623315b2.jpg"},{"id":70368770,"identity":"577d33c6-058d-487a-95f4-755b89647f35","added_by":"auto","created_at":"2024-12-02 14:29:21","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":63835,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffects of different interventions on running distance, speed, time and V̇O\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003emax\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eE: Exercise group; EMHOT30min: post exercise MHOT 30min group; EMHOT60min: post exercise MHOT 60min group; (a) : Running Distance; (b) : Running Speed;\u003c/p\u003e\n\u003cp\u003e(c) : Running Time; (d) : V̇O\u003csub\u003e2\u003c/sub\u003emax. \u003csup\u003e\u003cstrong\u003e*\u003c/strong\u003e\u003c/sup\u003e Significantly different from pre-intervention (\u003cem\u003eP \u0026lt; 0.05\u003c/em\u003e); \u003csup\u003e\u003cstrong\u003e#\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e \u003c/strong\u003esignificantly different from E group (\u003cem\u003eP \u0026lt; 0.05\u003c/em\u003e); \u003csup\u003e\u003cstrong\u003e△\u003c/strong\u003e\u003c/sup\u003e significantly different from EMHOT30min group (\u003cem\u003eP \u0026lt; 0.05\u003c/em\u003e).\u003c/p\u003e","description":"","filename":"Figure2.EffectsofdifferentinterventionsonrunningdistancespeedtimeandVO2max.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5440032/v1/2cf03d2d53669d4b2da4ed21.jpg"},{"id":70366915,"identity":"c5f83bfa-1186-4bf1-8ed2-cf137512a04a","added_by":"auto","created_at":"2024-12-02 14:21:22","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":15462,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffects of different interventions on serum CK, LDH and LA\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eC: Control group; E: Exercise group; EMHOT30min: post exercise MHOT 30min group;\u0026nbsp;\u0026nbsp; EMHOT60min: post exercise MHOT 60min group;\u003c/p\u003e\n\u003cp\u003e(a) : CK; (b) : LDH; (c) : LA;\u003csup\u003e\u003cstrong\u003e#\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e \u003c/strong\u003esignificantly different from E group (\u003cem\u003eP \u0026lt; 0.05\u003c/em\u003e).\u003c/p\u003e","description":"","filename":"Figure3.EffectsofdifferentinterventionsonserumCKLDHandLA.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5440032/v1/73fd9bdcf42e5708d81a069b.jpg"},{"id":70366911,"identity":"a18cc867-8d9c-4109-aec2-1f935b034d8d","added_by":"auto","created_at":"2024-12-02 14:21:21","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":63818,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffects of different interventions on serum SOD and MDA, CAT, TAOC\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eC: Control group; E: Exercise group; EMHOT30min: post exercise MHOT 30min group;\u0026nbsp;\u0026nbsp; EMHOT60min: post exercise MHOT 60min group;\u003c/p\u003e\n\u003cp\u003e(a) : SOD; (b) : MDA; (c) : CAT; (d) : TAOC;\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e\u003cstrong\u003e*\u003c/strong\u003e\u003c/sup\u003e significantly different from C group (\u003cem\u003eP \u0026lt; 0.05\u003c/em\u003e).\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e\u003cstrong\u003e#\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e \u003c/strong\u003esignificantly different from E group (\u003cem\u003eP \u0026lt; 0.05\u003c/em\u003e).\u003c/p\u003e","description":"","filename":"Figure4.EffectsofdifferentinterventionsonserumSODandMDACATTAOC.png","url":"https://assets-eu.researchsquare.com/files/rs-5440032/v1/28c4179cfb771e471b2503f0.png"},{"id":110150276,"identity":"b9cd2859-321f-4ec2-9806-ef6636003e74","added_by":"auto","created_at":"2026-05-28 10:10:57","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":634863,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5440032/v1/30252304-8fd1-4bf6-9fc2-bc0e185956a5.pdf"},{"id":70366910,"identity":"c2823424-3a98-4337-ac6f-9e170f009e3a","added_by":"auto","created_at":"2024-12-02 14:21:21","extension":"jpg","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":11710,"visible":true,"origin":"","legend":"","description":"","filename":"RatscompletedexerciseprotocolandMHOTinterventionprocedure.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5440032/v1/89f790c391b150f7662baa28.jpg"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of Varying Durations of One-Week Mild Hyperbaric Oxygen Therapy on Fatigue Recovery After Endurance Exercise in Rats","fulltext":[{"header":"Background","content":"\u003cp\u003ePhysiological and psychological demands during training and competition generate fatigue and can reduce an athlete\u0026acute;s sport-specific performance\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. A wide range of recovery modalities are now used as integral parts of the training and competition programs of elite athletes to help attenuate fatigue and enhance recovery \u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. As a World Anti-doping Agency (WADA) approved treatment, oxygen therapy has been used to improve exercise performance in sports \u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. Hyperoxia supplementation influences the cardiorespiratory, nervous, and endocrine systems, as well as energy metabolism, potentially leading to improvements in both performance and recovery \u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. Additionally, Hyperbaric Oxygen Therapy (HBOT) is an adjunct therapy for athletes to enhance recovery, minimize post-exercise muscle damage and swelling, and improve tissue remodeling following muscle injury \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. On the other hand, it has been shown that hyperoxia and HBOT treatments may lead to potential side effects such as barotrauma, oxygen toxicity, and the risk of increased oxidative stress with prolonged hyperoxia exposure \u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. In fact, there is ongoing controversy regarding the effectiveness of HBOT versus hyperoxia therapy in enhancing sports performance and recovery, with studies showing inconclusive results \u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eMild Hyperbaric Oxygen Therapy (MHOT), characterized by exposure to slightly elevated atmospheric pressure 1.24\u0026ndash;1.29 atmosphere absolute (ATA) and enriched oxygen levels (25\u0026ndash;40% oxygen), emerges as a promising alternative to mitigate exercise-induced fatigue \u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. By avoiding the pitfalls of barotrauma and excessive reactive oxygen species production, MHOT is poised to offer therapeutic advantages in metabolic regulation and disease management. Its role in combating muscle atrophy and enhancing cellular metabolism makes it a compelling option for sports recovery \u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Recent research has explored the application of MHOT in sports to assess its impact on recovery. Findings suggest that MHOT shows promise as an effective method for improving mood states following high-intensity training \u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. Additionally, studies suggest that 1.3 ATA oxygen therapy is an effective strategy for enhancing cardiac parasympathetic reactivation, which may contribute to improved subsequent sports performance \u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThere is a lack of research on how different durations of MHOT affect post-exercise recovery. This gap in knowledge has hindered both research and practical applications of MHOT in sports science. Additionally, there aren't enough animal studies exploring how MHOT specifically impacts fatigue recovery after exercise. To address these issues, we conducted a study on rats to investigate how different durations of acute MHOT interventions affect fatigue mitigation after endurance exercise. Our research was based on existing studies of hyperoxia, HBOT, and MHOT in relation to exercise, as well as the equipment available to us and practical considerations.\u003csup\u003e[\u003cspan additionalcitationids=\"CR6 CR7 CR8\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. We hypothesized that MHOT will improve fatigue recovery in rats after endurance exercise compared to a standard air environment (1 ATA, 20.9% oxygen), and we expect that different durations of MHOT treatment will yield varying levels of effectiveness. This study aims to investigate how MHOT affects fatigue recovery following one week of endurance exercise and to identify the most effective treatment duration. Ultimately, our findings are intended to provide valuable insights for future research and practical applications of MHOT in sports science and exercise recovery.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eAnimals and Experimental design\u003c/h2\u003e \u003cp\u003eThirty-two male Wistar rats (age: 6 weeks, weight: 190\u0026thinsp;~\u0026thinsp;210 g) were provided by the Beijing Vital River Laboratory Animal Technology Co., Ltd. All rats were raised in ventilated caging system separately under a 12:12 h light-dark cycle (23\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0℃ and 45%-55% humidity). The rats were divided into four groups of eight at random: control group (C), exercise group (E), post exercise MHOT 30min group (EMHOT30min) and post exercise MHOT 60min group (EMHOT60min). The C group underwent normal feeding without any exercise or recovery intervention. After one week of acclimatization with feeding and watering, all rats in the E, EMHOT30min, and EMHOT60min groups were trained for 1 week on the treadmill (10 m/min speed, 0\u0026deg; gradient, 10 minutes) to familiarize them with the exercise regimen. Following treadmill adaptation, these groups underwent a 1-week aerobic treadmill training program, consisting of six sessions with 90 minutes of treadmill running per day (60%-65% maximal oxygen uptake (V̇O\u003csub\u003e2\u003c/sub\u003emax), 65%-70% V̇O\u003csub\u003e2\u003c/sub\u003emax, and 70%-75% V̇O\u003csub\u003e2\u003c/sub\u003emax for 30 minutes each, at a 0\u0026deg; gradient). After completing the exercise protocol, each group received different interventions. The E group experienced natural environment recovery (1 ATA, 20.9% oxygen concentration), while the EMHOT30min and EMHOT60min groups were exposed to MHOT conditions (1.25 ATA, 26%-28% oxygen concentration) for 30 minutes and 60 minutes, respectively. During the pre-exercise baseline and after the 1-week intervention the E, EMHOT30min and EMHOT60min groups underwent an aerobic exercise capacity test. Following, the rats were anesthetized, and blood was collected to assess the complete blood count and biochemical analyses of enzyme activity. The study design is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. All the procedures were approved by the Animal Ethical Committee of the China Institute of Sports Science in accordance with the guidelines of experimental animal use.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eExercise protocol\u003c/h3\u003e\n\u003cp\u003eRats in the E, EMHOT30min and EMHOT60min groups underwent aerobic treadmill (DSPT-202, China) training for 90 min every day for 1 week (six times). The aerobic treadmill training protocol consisted of a 5-minute warm-up followed by three consecutive sessions of moderate aerobic exercise. Each session was performed at increasing intensities of 60%-65% V̇O\u003csub\u003e2\u003c/sub\u003emax, 65%-70% V̇O\u003csub\u003e2\u003c/sub\u003emax, and 70%-75% V̇O\u003csub\u003e2\u003c/sub\u003emax, respectively, with each period lasting 30 minutes \u003csup\u003e[11, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. The total exercise duration was 90 minutes, encompassing three consecutive periods \u003csup\u003e[13\u0026minus;15]\u003c/sup\u003e. The protocol did not include intermittent rest breaks during any of the treadmill exercises. Finally, the protocol concluded with a 5-minute cool-down period. This exercise protocol was notably time-consuming and physically demanding, leading to exhaustion among the rats.\u003c/p\u003e\n\u003ch3\u003eTreatment\u003c/h3\u003e\n\u003cp\u003eThe E, EMHOT30min, and EMHOT60min groups were exposed to different recovery modalities during the experiment. The rats in the E group were placed in a rearing cage within their natural environment routine quiet rest conditions (1 ATA, 20.9% oxygen, temperature ranging from 20 to 26\u0026deg;C) after each exercise session. All treatments procedures were designed based on prior published studies on HBOT and sports, MHOT and sports \u003csup\u003e[\u003cspan additionalcitationids=\"CR7 CR8\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. The EMHOT30min and EMHOT60min groups were subjected to mild hyperbaric oxygen therapy using a chamber (Beijing Chuang Xin Kaida Technology Co., Ltd). This chamber featured an oxygen standard soft cabin (210 cm in length, 72 cm in width), allowing the rats to lie down comfortably in a rearing cage, and a compressor control box (56 cm in length, 50 cm in width, 99 cm in height) that housed an oxygen concentrator and an air compressor. The atmospheric pressure and oxygen concentration were precisely regulated by a computer-assisted system within the control box. The device is configured with preset oxygen pressure and concentration settings, which cannot be adjusted during the intervention.\u003c/p\u003e \u003cp\u003eIn the EMHOT30min group, the MHOT intervention was administered post-exercise for 30 minutes at 1.25 ATA with 26%-28% oxygen concentration, based on the device's preset configuration. In the EMHOT60min group, the MHOT intervention lasted for 60 minutes under the same pressure and oxygen concentration conditions. These parameters were consistent with those recommended by MHOT-related research \u003csup\u003e[\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. The chamber conditions were maintained at a temperature of 22\u0026thinsp;\u0026plusmn;\u0026thinsp;8\u0026deg;C with a relative humidity of 40\u0026ndash;60%. Before entering the oxygen chamber, rats were provided with food and water as usual, and their performance and condition were closely monitored throughout the intervention period.\u003c/p\u003e\n\u003ch3\u003eAerobic exercise capacity test\u003c/h3\u003e\n\u003cp\u003eRats in the E, EMHOT30min and EMHOT60min groups underwent V̇O\u003csub\u003e2\u003c/sub\u003emax test to assess aerobic exercise capacity. This test was conducted both at baseline and following the 1-week intervention. V̇O\u003csub\u003e2\u003c/sub\u003emax was measured to determine the exercise treadmill intensity (running speed) and was evaluated with the Columbus Oxymax Lab Animal Monitoring System (Columbus, USA). Experimental parameters included oxygen uptake (V̇O\u003csub\u003e2\u003c/sub\u003e ) and respiratory exchange ratio (RER), running distance, speed, and time were assessed using a Columbus Oxymax Lab Animal Monitoring System and an animal treadmill chamber. A gas analyzer was calibrated with ambient air and a reference gas in a room with stable temperature and humidity. Before starting the test, the body mass of the rats was measured. The test protocol began with a 2-minute warm-up period at a speed of 12 m/min. After 3 minutes, the treadmill speed was elevated to 15 m/min. Subsequently, the treadmill speed was increased by 5 m/min every 3 minutes, while maintaining the treadmill slope at 0\u0026deg;, until the rats reached volitional exhaustion \u003csup\u003e[17]\u003c/sup\u003e. We employed several criteria to ensure the V̇O\u003csub\u003e2\u003c/sub\u003emax and maximum aerobic exercise capacity were reached during the rat tests. These criteria included: observing that the increase in V̇O\u003csub\u003e2\u003c/sub\u003e was less than 5% despite the increased workload, noting RER above 1.00, and identifying signs of exhaustion such as unwillingness to run, feeble kicking of hind legs, and mental sluggishness. As soon as any two of these criteria were met, we terminated the test and recorded the corresponding test values \u003csup\u003e[11,1\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e\n\u003ch3\u003eSample collection\u003c/h3\u003e\n\u003cp\u003eBefore euthanasia, the rat was fasted for 12 hours to standardize metabolic conditions. 24 hours After aerobic exercise capacity test, Animals were anaesthetized prior to euthanasia to ensure they were unconscious and experienced minimal discomfort. All rats were anesthetized with an intraperitoneal injection, 10% chloral hydrate, according to the ratio of 0.35\u0026thinsp;~\u0026thinsp;0.4 ml/100 g of weight, the depth of anaesthesia was controlled by the observation of pinna and withdrawal reflexes. Then blood was collected through the abdominal aorta. After blood sample collection rat were euthanized immediately through cervical dislocation.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eComplete blood count\u003c/h2\u003e \u003cp\u003eA total of 1.5 ml of blood was extracted from the abdominal aorta of the rats and treated with EDTA to prevent coagulation. The collected blood samples underwent analysis using the Mindray BC-5000 Automatic Hematology Analyzer (Mindray Bio-Medical Electronics Co., Ltd, Shenzhen, China) to assess various parameters. Complete blood count detection indicators include Red Blood Cell (RBC); Hemoglobin (HGB); Hematocrit (HCT); Mean Corpuscular Volume (MCV); Mean Corpuscular Hemoglobin (MCH); Mean Corpuscular Hemoglobin Concentration (MCHC); RBC Distribution Width (RDW); Platelet Count (PLT); Mean Platelet Volume (MPV); White Blood Cell (WBC); Neutrophil Count (NEUT-abs); lymphocytes Count (LYMPH-abs); Monocytes Count (MONO-abs); Eosinophils Count (EOS-abs); Basophils Count (BASO-abs); Neutrophil percentage (NEUT%); lymphocytes percentage (LYMPH%); Monocytes percentage (MONO%); Eosinophils percentage (EOS%); Basophils percentage (BASO%).\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eBiochemical analyses of serum enzyme activity\u003c/h3\u003e\n\u003cp\u003eA total of 4.5 mL of blood was drawn from the rats in each group and collected into serum separator tubes. After centrifugation at 3500 revolutions per minute at 4\u0026deg;C for 20 minutes, serum samples were obtained. These samples were divided into multiple aliquots and stored at -80\u0026deg;C until further analysis. The levels of serum Creatine Kinase (CK) and Lactate Dehydrogenase (LDH) were assessed using VITROS Chemistry CK and LDH DT slides (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). Serum levels of Lactate (LA) and Catalase (CAT) were determined using commercially available kits according to the manufacturers\u0026rsquo; instructions (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). The assessment of serum Malondialdehyde (MDA) levels was conducted following the Yagi method \u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e. This method involves the measurement of Thiobarbituric acid (TBA) reactive substances, which serve as reaction products. The quantification of these substances was performed at a wavelength of 532 nm using spectrophotometry. Superoxide dismutase (SOD) serum level was measured using the commercially available enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer\u0026rsquo;s instructions (Nanjing Jiancheng Bioengineering Institute, Nanjing, China). The assay detection limit of SOD was 3 U/ml, with intra-assay and inter-assay coefficients of variation (CV) of 9% and 15%, respectively. The determination of Total Antioxidant Capacity (TAOC) in serum was conducted through the Ferric ion reducing antioxidant power (FRAP) method. Optical density measurements were recorded at 593 nm using an enzyme-linked analyzer (Multiskan Asc, Thermo, USA).\u003c/p\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eAll measurement results data are presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD). Statistical analyses were performed using SPSS (version 22.0, IBM SPSS Statistics, Chicago, IL). Statistical significance was defined as \u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/em\u003e. The Kolmogorov\u0026ndash;Smirnov test was applied for testing normal distribution of data. A One-way Analysis of Variance (ANOVA) was employed to compare the complete blood count and serum enzyme activity measurements among the four groups. Post-hoc multiple comparisons were conducted using the Least Significant Difference (LSD) test or Dunnett\u0026rsquo;s test to further analyze and determine specific differences between the individual groups. For the comparison of aerobic exercise capacity test indicators within the same group before and after intervention, a matched samples \u003cem\u003et\u003c/em\u003e-test was utilized. Additionally, to compare these indicators between different groups, a one-way ANOVA was employed. A Kruskal\u0026ndash;Wallis test was used for non-normally distributed data. Furthermore, effect size estimates (Cohen\u0026rsquo;s d) were calculated to further assess efficacy. The data were interpreted with effect sizes categorized as small (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.2\u0026ndash;0.5), medium (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.5\u0026ndash;0.8), or large (\u003cem\u003ed\u003c/em\u003e\u0026thinsp;\u0026ge;\u0026thinsp;0.8) \u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003eEffects of different interventions on aerobic exercise capacity\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e illustrates the effects of the different interventions on aerobic exercise capacity in rats. Post-intervention running distance, running speed, and running time were increased compared with pre-intervention in the E group (distance: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.44; speed: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.52; time: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.45), the EMHOT30min group (distance: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.88; speed: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.83; time: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.83), and the EMHOT60min group (distance: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.79; speed: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.84; time: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.72). Post-intervention, the EMHOT60min group showed a significant increase in running distance and speed compared to the E group (distance: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.63; speed: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.56) and the EMHOT30min group (distance: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.51; speed: \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.50). Additionally, post-intervention running time in the EMHOT60min group was significantly higher compared to the E group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.62). Finally, post-intervention V̇O\u003csub\u003e2\u003c/sub\u003emax was significantly increased compared to pre-intervention in the EMHOT30min group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.45) and the EMHOT60min group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.60). The EMHOT60min group also showed a significant increase in V̇O\u003csub\u003e2\u003c/sub\u003emax compared to the E group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.61).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003eEffects of different interventions on complete blood count\u003c/h2\u003e\n \u003cp\u003eThe results from Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e highlight various changes in blood parameters among the groups. Specifically, the EMHOT60min group showed a statistically significant increase in HGB levels post-intervention compared to the E group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.85). Regarding MCH levels, the EMHOT30min group had significantly higher MCH levels compared to the E group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.52). The EMHOT60min group exhibited significant increases in MCH levels compared to both the E group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.88) and the EMHOT30min group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.60). Concerning MCHC levels, the EMHOT30min group showed significant increases compared to the E group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.52). The EMHOT60min group had significantly elevated MCHC levels compared to the C group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.65), the E group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.89), and the EMHOT30min group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05,\u0026nbsp;\u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.73) No significant differences were observed in other complete blood count parameters among the four groups.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003ePost-intervention effects on complete blood count\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eComplete Blood Count\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003cp\u003egroup(n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eE group(n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eEMHOT30min group(n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eEMHOT60min group(n\u0026thinsp;=\u0026thinsp;6)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eRBC(x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e6\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/uL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eHGB (g/L)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e136\u0026thinsp;\u0026plusmn;\u0026thinsp;32.24\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e109.66\u0026thinsp;\u0026plusmn;\u0026thinsp;8.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e127.83\u0026thinsp;\u0026plusmn;\u0026thinsp;15.17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e134.66\u0026thinsp;\u0026plusmn;\u0026thinsp;6.56\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eHCT (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e35.08\u0026thinsp;\u0026plusmn;\u0026thinsp;4.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e31.58\u0026thinsp;\u0026plusmn;\u0026thinsp;3.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e34.55\u0026thinsp;\u0026plusmn;\u0026thinsp;4.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e36.05\u0026thinsp;\u0026plusmn;\u0026thinsp;2.27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eMCV(fL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e58.06\u0026thinsp;\u0026plusmn;\u0026thinsp;1.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e58.56\u0026thinsp;\u0026plusmn;\u0026thinsp;2.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e58.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e59.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eMCH(Pg)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.57\u003csup\u003e#△\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e21.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e21.96\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23\u003csup\u003e#△\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eMCHC(g/L)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e371.33\u0026thinsp;\u0026plusmn;\u0026thinsp;2.80\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e363.16\u0026thinsp;\u0026plusmn;\u0026thinsp;3.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e368.16\u0026thinsp;\u0026plusmn;\u0026thinsp;4.44\u003csup\u003e#\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e375.83\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31\u003csup\u003e*#△\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eRDW (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e11.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e12.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e12.43\u0026thinsp;\u0026plusmn;\u0026thinsp;0.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e12.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003ePLT (x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/UL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1113.33\u0026thinsp;\u0026plusmn;\u0026thinsp;182.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e985.66\u0026thinsp;\u0026plusmn;\u0026thinsp;316.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1027.16\u0026thinsp;\u0026plusmn;\u0026thinsp;191.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1114.50\u0026thinsp;\u0026plusmn;\u0026thinsp;283.02\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eMPV (fL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.63\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.83\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eWBC (x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/UL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eNEUT-abs (x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/UL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.51\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eLYMPH-abs (x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/UL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.29\u0026thinsp;\u0026plusmn;\u0026thinsp;0.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.04\u0026thinsp;\u0026plusmn;\u0026thinsp;0.54\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eMONO-abs (x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/UL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eEOS-abs (x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/UL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.008\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.020\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.122\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eBASO-abs (x10\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e/UL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.012\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.011\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.008\u0026thinsp;\u0026plusmn;\u0026thinsp;0.009\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.006\u0026thinsp;\u0026plusmn;\u0026thinsp;0.008\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eNEUT% (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e22.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e27.21\u0026thinsp;\u0026plusmn;\u0026thinsp;12.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e21.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e24.98\u0026thinsp;\u0026plusmn;\u0026thinsp;3.03\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eLYMPH% (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e69.71\u0026thinsp;\u0026plusmn;\u0026thinsp;4.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e68.26\u0026thinsp;\u0026plusmn;\u0026thinsp;13.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e69.03\u0026thinsp;\u0026plusmn;\u0026thinsp;1.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e66.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eMONO% (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e6.30\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.7\u0026thinsp;\u0026plusmn;\u0026thinsp;2.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e7.93\u0026thinsp;\u0026plusmn;\u0026thinsp;1.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e8.01\u0026thinsp;\u0026plusmn;\u0026thinsp;2.24\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eEOS% (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e1.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eBASO%(%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.66\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\"\u003eC: Control group; E: Exercise group; EMHOT30min: post exercise MHOT 30min group; EMHOT60min: post exercise MHOT 60min group;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cstrong\u003e*\u003c/strong\u003e\u003c/sup\u003e significantly different from C group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/em\u003e);\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cstrong\u003e#\u003c/strong\u003e\u003c/sup\u003e significantly different from E group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/em\u003e);\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\"\u003e\u003csup\u003e\u003cstrong\u003e△\u003c/strong\u003e\u003c/sup\u003e significantly different from EMHOT30min group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/em\u003e);\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003eEffects of different interventions on serum enzyme activity\u003c/h2\u003e\n \u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e illustrates the changes in CK, LDH, and LA levels. Post-intervention, groups C (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.79), EMHOT30min (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.69), and EMHOT60min (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.86) exhibited statistically significant reductions in CK levels compared to group E. In contrast, LDH levels showed no significant differences among the four groups. For LA levels, groups C (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.67), EMHOT30min (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.77), and EMHOT60min (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.01, \u003cem\u003eES\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.79) also demonstrated significant reductions compared to group E.\u003c/p\u003e\n \u003cp\u003eAt the post-intervention assessment, noticeable differences in SOD and TAOC levels were observed among the groups. The EMHOT30min group displayed statistically significant higher SOD and TAOC levels compared to both the C group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.79\u003c/em\u003e), (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05, ES\u0026thinsp;=\u0026thinsp;0.52\u003c/em\u003e) and the E group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.84\u003c/em\u003e), (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.68\u003c/em\u003e). Similarly, the EMHOT60min group exhibited a statistically significant increase in SOD and TAOC levels at the post-intervention time point compared to both the C group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.81\u003c/em\u003e), (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.69\u003c/em\u003e) and the E group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.86\u003c/em\u003e), (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.79\u003c/em\u003e). Figure \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e reveals distinct findings in MDA levels, with the EMHOT30min group showing a significant reduction compared to the E group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.67\u003c/em\u003e) and the EMHOT60min group demonstrating statistically significant decreases compared to both the C group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.60\u003c/em\u003e) and the E group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.01, ES\u0026thinsp;=\u0026thinsp;0.74\u003c/em\u003e). Figure \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e shows variations in CAT levels, where the EMHOT30min group had a statistically significantly higher CAT levels compared to the C group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05, ES\u0026thinsp;=\u0026thinsp;0.51\u003c/em\u003e), and the EMHOT60min group exhibited statistically significant increases compared to both the C group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05, ES\u0026thinsp;=\u0026thinsp;0.56\u003c/em\u003e) and the E group (\u003cem\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.05, ES\u0026thinsp;=\u0026thinsp;0.46\u003c/em\u003e).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eFatigue model following one week of endurance exercise\u003c/h2\u003e \u003cp\u003eIn the present study, exercise exhaustion was determined by specific criteria: the rats were unable to maintain the predetermined speed, their abdomens stayed in contact with the runway surface, and their hind legs showed signs of weakness. The rats were considered to have reached complete exhaustion after continuous exposure to sound, light, and mechanical stimulation, which eventually caused them to stop running \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. After completing a series of six endurance exercise sessions, rats in the E, EMHOT30min, and EMHOT60min groups exhibited noticeable physical changes indicative of fatigue. These included slower reaction times, weaker kicking motions, and even instances where the rats assumed a supine position, all clear signs of exhaustion \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. These observations suggest that the endurance exercise fatigue protocol used in this study successfully aligns with the established criteria for modeling exercise-induced fatigue in rats.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eImpact of MHOT on aerobic exercise capacity following one week of endurance exercise\u003c/h2\u003e \u003cp\u003eThe results show the MHOT intervention (30min and 60min groups) significantly increased rats aerobic exercise capacity. Similar results have been observed in related protocols involving MHOT exposure in rats. For instance, running ability improved in rats exposed to MHOT, attributed to the enhanced oxidative capacity of the soleus and plantaris muscle fibers, along with an increase in the activity of their spinal motoneurons following MHOT intervention \u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. Another study highlighted that the combination of MHOT and training can improve aerobic exercise performance by enhancing oxidative and glycolytic capacities, as well as the expression of proteins involved in mitochondrial biogenesis in mice \u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. The study suggests that chronic intermittent MHOT exposure may aid in muscle damage recovery by upregulating heat shock protein 70 (HSP70), thereby improving muscular adaptation to exercise training \u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. Additionally, MHOT has been shown to have beneficial effects in both endurance and interval training, leading to improved exercise capacity in highly trained mice \u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. Research has also indicated that exposure to hyperbaric conditions, in combination with endurance training, can not only enhance oxidative and glycolytic capacities but also increase the protein levels of key factors such as mitochondrial transcription factor A, dynamin-related protein-1, and HSP70 \u003csup\u003e[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. A study suggested that MHOT does not enhance mitochondrial content acutely, but regular treatment might lead to upregulation of muscle mitochondrial biogenesis over time, increasing peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) mRNA levels \u003csup\u003e[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e. In this study, we believe there is a possibility that MHOT may have a similar intervention effect, indicating its potential to enhance aerobic endurance by influencing key factors related to cellular energy production, mitochondrial function, and oxidative stress response. We propose that MHOT intervention could increase the dissolved oxygen content in plasma, improve the oxidative capacity of motor neurons, and thereby enhance their excitability during exercise. Additionally, MHOT may improve oxygen utilization and increase tolerance to aerobic exercise. In the aerobic exercise capacity test conducted in this study, the EMHOT60min group outperformed the EMHOT30min group. This difference in performance could be due to the longer exposure duration of 60 minutes in the MHOT intervention, suggesting a more sustained response within the body.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003eImpact of MHOT on complete blood count following one week of endurance exercise\u003c/h2\u003e \u003cp\u003eThe findings of this study indicate that MHOT intervention significantly enhanced the recovery of blood hemoglobin, with notable improvements in restoring blood oxygen levels. Specifically, the EMHOT60min group showed superior results compared to the EMHOT30min group, suggesting that a longer exposure of 60 minutes to MHOT more effectively restored blood oxygen content than the 30-minute exposure. This is consistent with other studies that have reported increases in peripheral oxygen saturation and blood flow following MHOT intervention \u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e. The authors believe that exposure to MHOT may lead to an increase in blood flow and metabolism. This assertion is based on the understanding that MHOT has the capacity to augment the quantity of dissolved oxygen present in the plasma, consequently enhancing metabolic processes within cells and tissues \u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e. Another study suggested that MHOT intervention significantly increases peripheral oxygen saturation, skin blood flow, and hemodynamics in finger capillaries in healthy individuals \u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. This effect is achieved by increasing the amount of oxygen bound to hemoglobin in red blood cells and elevating the levels of dissolved oxygen in the plasma \u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. Additionally, hyperoxia enhances micro vessel oxygenation through improved gas exchange, which helps maintain blood oxygen stability and supports the blood oxygen transport system \u003csup\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/sup\u003e. Studies also indicate that MHOT enhances the body's oxygen-carrying capacity and accelerates oxygen diffusion throughout the body, improving micro vessel oxygenation and stabilizing the blood oxygen transport system \u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e. Therefore, in this study, we believe that MHOT intervention facilitates a progression from stress compensation to adaptive feedback. The differing effects of 30-minute versus 60-minute MHOT interventions likely reflect the body's adaptive responses, suggesting that longer interventions may produce distinct responses and adaptations compared to shorter ones.\u003c/p\u003e \u003cp\u003e \u003cb\u003eImpact of MHOT on blood muscle damage and acid metabolites after one week of endurance exercise\u003c/b\u003e \u003c/p\u003e \u003cp\u003eResults indicate that muscle damage and levels of metabolites such as CK and lactate (LA) were significantly reduced in the MHOT intervention groups, with no significant difference between the 30-minute and 60-minute exposure durations. Some studies have shown that lactate concentration during the 30-minute recovery period is notably lower in subjects receiving MHOT compared to controls after maximal exercise \u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/sup\u003e. This aligns with our findings, suggesting that MHOT can alleviate peripheral fatigue and potentially enhance the clearance of fatigue-inducing substances generated by intense exercise \u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/sup\u003e. Similarly, our published study found that repeated MHOT interventions reduced serum markers of muscle damage and metabolites after exercise-induced fatigue \u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. We believe MHOT improves oxygen diffusion from capillaries to adjacent cells, increases tissue and fluid oxygen content, supports tissue repair, and accelerates metabolite removal by raising dissolved oxygen levels. However, variations in CK, LDH, and LA levels might be influenced by factors such as the age of rats, their feeding environment, instrument calibration, test quality control, and reagents used. Therefore, further research with strictly controlled conditions is needed to fully understand the impact of MHOT intervention on these blood indicators.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eImpact of MHOT oxidative stress after one week of endurance exercise\u003c/h2\u003e \u003cp\u003eThe results of serum oxidative stress indicators revealed that MHOT intervention significantly enhanced antioxidant levels, as evidenced by reduced MDA and increased SOD, CAT, and TAOC. These findings are consistent with previous reports indicating that MHOT can decrease muscle oxidative stress and improve antioxidant levels in rats with metabolic syndrome \u003csup\u003e[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e. Additionally, MHOT has been shown to counteract the age-related decline in skeletal muscle oxidative capacity by boosting oxidative metabolism in cells and tissues \u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/sup\u003e. Studies in dogs have also demonstrated increased glutathione peroxidase activity following MHOT intervention, suggesting that MHOT effectively modulates oxidative stress and stabilizes the organism's internal environment \u003csup\u003e[\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e. We believe that MHOT can effectively reduce free radical-induced tissue damage, lower lipid peroxidation, and maintain the oxidative-antioxidant balance, which benefits aerobic performance. Consequently, MHOT intervention may aid in eliminating free radicals, thereby preventing potential pathways to apoptosis induced by oxygen free radicals. Furthermore, MHOT intervention suggests that a longer adaptive period, such as a 60-minute exposure, may provide more extended adaptation effects and sustained tolerance. This longer duration likely facilitates a more pronounced adaptive response within the body and maintains tolerance to the intervention over a more extended period.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003eStudy limitations\u003c/h2\u003e \u003cp\u003eThe study has several limitations that should be considered. The sample size was small and comprised only male rats. Additionally, blood indicators were not measured immediately after the intervention or at other time points, such as 1-hour post-exercise, which could reveal changes not captured in this study. Therefore, the results regarding blood indicators should be interpreted with caution. Furthermore, the study did not explore the underlying molecular pathways affected by MHOT intervention, leaving the mechanisms behind its fatigue-relieving effects unclear. The experimental model was also limited to investigating the effects of a 1-week MHOT treatment. Future research should focus on understanding the molecular pathways involved, include larger and more diverse samples, and examine the long-term effects of MHOT to provide a more comprehensive view of its mechanisms and potential for alleviating exercise fatigue in various contexts.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eTo our knowledge, this study is among the few that investigate and compare the effects of different MHOT intervention durations on fatigue following one week of endurance exercise in rats. The results indicate that both 30-minute and 60-minute MHOT interventions positively impacted the reduction of endurance exercise-induced fatigue. These interventions helped preserve aerobic exercise capacity and improve oxidative metabolism. Our findings suggest that MHOT's effectiveness in alleviating fatigue is likely due to enhanced aerobic metabolism, increased antioxidant capacity, and maintained internal environmental stability. The superior effectiveness of the 60-minute MHOT intervention compared to the 30-minute protocol may be attributed to its longer cumulative exposure time, which likely provides a more pronounced adaptive response. Therefore, a 60-minute MHOT intervention is recommended as a more effective protocol for promoting fatigue recovery after endurance exercise.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the procedures were approved by the Animal Ethical Committee of the China Institute of Sports Science (CISSLA-2020062801) in accordance with the guidelines of experimental animal use. Animals received humane care in compliance with the China Institute of Sports Science and the guide for the care and use.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. All authors declare that there are no conflicts of interest.\u003c/p\u003e\n\u003ch2\u003eFunding\u003c/h2\u003e\n\u003cp\u003eThis work was supported by the General Research of Natural Science Foundation of Beijing (5212020) and the Doctoral Research Initiation Fund Project of Hebei Normal University (L2024\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\n\u003cp\u003eCY Qu, JX Zhao, MX Xu designed the experiments. P Huang and CY Qu, X Geng collected and analyzed the data. CY Qu, Santiago Lorenzo and ZJ Rao and JX Zhao edited the manuscript. All authors read and approved the submitted version.\u003c/p\u003e\n\u003ch2\u003eAcknowledgements\u003c/h2\u003e\n\u003cp\u003eThis work was supported by the Laboratory of China Institute of Sport Science and Hebei Normal University Physical Education College. The authors thank all the participants for their efforts and help in this experiment.\u003c/p\u003e\n\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSkorski S, Mujika I, Bosquet L, Meeusen R, Coutts AJ, Meyer T. The Temporal Relationship Between Exercise, Recovery Processes, and Changes in Performance. 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Enzyme Res. 2010;19(2010):824763.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIshibashi M, Hayashi A, Akiyoshi H, Ohashi F. The influences of hyperbaric oxygen therapy with a lower pressure and oxygen concentration than previous methods on physiological mechanisms in dogs. J Vet Med Sci. 2015;77(3):297\u0026ndash;304.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Fatigue, Mild hyperbaric oxygen therapy, Recovery, Rats, Intervention time","lastPublishedDoi":"10.21203/rs.3.rs-5440032/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5440032/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eFatigue is a common physiological phenomenon in sports. There are reports describing the beneficial effects of exposure to Mild Hyperbaric Oxygen Therapy (MHOT) on metabolic diseases. However, the effects of MHOT on exercise-induced fatigue have not been fully investigated. Therefore, this study aimed to analyze the effects of different MHOT intervention time protocols (30 min and 60 min) on one week of endurance exercise-induced fatigue in rats.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA total of 32 male Wistar rats (aged 6 weeks) were randomly assigned into to control group (C), exercise group (E), MHOT for 30min after exercise group (EMHOT30min) and MHOT for 60min after exercise group (EMHOT60min), with 8 rats in each group. In the exercise group, rats underwent treadmill exercise sessions lasting 90 minutes each day, conducted six times a week, once a day for one week. These exercise sessions were tailored based on the measurement range of maximum oxygen uptake. After each exercise session, the E group underwent a routine quiet rest (1 ATA, 20.9% oxygen). Conversely, the EMHOT30min and EMHOT60min groups were exposed to an MHOT environment for 30 minutes and 60 minutes, respectively (1.25ATA, 26%-28% oxygen concentration). Baseline measurements and aerobic exercise capacity tests were conducted before and after the one-week intervention period. At the end of the intervention, a complete blood count and biochemical analyses of enzyme activity were also performed.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe results show that the MHOT intervention groups significantly increased aerobic exercise capacity and promoted the recovery of blood oxygen content. Moreover, the EMHOT60min group was better than the EMHOT30min group (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05). Muscle damage and metabolite levels induced by one week of endurance exercise were significantly reduced in the MHOT intervention groups, with no significant difference observed between the two MHOT groups (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;.05). The MHOT intervention also significantly enhanced antioxidant levels, compared with EMHOT30min group, the effect of EMHOT60min group is more obvious (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThese data suggest that both the 30-minute and 60-minute MHOT interventions effectively facilitated the reduction of fatigue in rats after one week endurance exercise. Moreover, the 60-minute MHOT intervention demonstrated a superior effect on aerobic exercise capacity and antioxidant capacity. This enhanced effect of the 60-minute protocol might be attributed to the cumulative time-response relationship inherent in MHOT intervention time protocol.\u003c/p\u003e","manuscriptTitle":"Impact of Varying Durations of One-Week Mild Hyperbaric Oxygen Therapy on Fatigue Recovery After Endurance Exercise in Rats","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-02 14:21:17","doi":"10.21203/rs.3.rs-5440032/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ba6d2d00-519c-46d6-b26c-bc75d5edf45c","owner":[],"postedDate":"December 2nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-28T10:10:41+00:00","versionOfRecord":[],"versionCreatedAt":"2024-12-02 14:21:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5440032","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5440032","identity":"rs-5440032","version":["v1"]},"buildId":"FbvkV6FR0MCFSLy54lSbu","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}