Do Assessments of Cardiorespiratory and Muscular Fitness Influence Subsequent Reported Physical Activity? A Randomized Controlled Trial.

Abstract BackgroundClinicians strive to motivate healthy lifestyle behaviors such as exercise. Cardiorespiratory fitness (CRF) and muscular strength are important for good health and their measurement could potentially provide motivation to exercise. We investigated if measurements of CRF and muscular fitness (MF) would influence subsequent self-reported physical activity. MethodsVolunteer subjects at a State Fair were randomized in 1:1 parallel fashion to control and intervention groups. The baseline Exercise Vital Sign (EVS) and type of physical activity were obtained from all subjects. The intervention group received estimated maximum oxygen uptake (VO2max) using a step test and muscular strength using a hand grip dynamometer with age-specific norms for both measurements. All subjects were provided exercise recommendations and follow up surveys during the following year regarding their EVS and physical activity. Results1315 individuals (656 intervention, 659 control) were randomized with one year follow up data obtained from 823 subjects (62.5%). Baseline mean EVS was 213 min/week. No change in EVS was found either group at follow-up (p=0.99). Subjects who were less active at baseline (EVS<150) did show an increase in EVS (86 to 146) at 6 months (p<0.05). At 3 months the intervention group increased resistance training (29.1% to 42.8%) compared to controls (26.3% to 31.4%) (p<0.05). Lifestyle physical activity increased in the intervention group at 3 months (27.7% to 29.1%) and 6 months (25%) whereas it declined in the control group at 3 months (24.4% to 20.1%) and 6 months (18.7%) (p<0.05). ConclusionProviding VO2max estimates and grip strength did not produce an increase in overall physical activity. The EVS and exercise recommendations did however result in increased physical activity in less active individuals. In a very active population the VO2max estimate and measured grip strength did increase lifestyle activity and resistance training. Wider adoption of these measures could be effective in promoting physical activity and resistance training.Trial Registration Numberclinicaltrials.gov NCT03518931 Registered 05/08/2018 -retrospectively registered https://clinicaltrials.gov/ct2/results?cond=&term=NCT03518931&cntry=&state=&city=&dist=