Providing Estimates Of Fitness May Influence Subjects’ Exercise

Abstract

PURPOSE: We investigated if providing measurements of cardiorespiratory and muscular fitness would influence subsequent self-reported physical activity. METHODS: The Exercise Vital Sign and current types of physical activity were obtained from 1315 individuals attending the 2014 and 2015 Minnesota State Fairs. The baseline mean Exercise Vital Sign was 213 min/week. Subjects were randomized in 1:1 fashion to control and intervention groups. The 656 intervention subjects were provided with personal measurements and age appropriate norms of cardiorespiratory fitness using a validated non-maximal step test to estimate VO2max and muscular strength using a hand grip dynamometer. All subjects were provided exercise recommendations based on current standards and follow up surveys conducted to determine subsequent physical activity. Follow up Exercise Vital Sign and physical activity type was obtained from 823 subjects (62.5%) over the following year. RESULTS: No significant changes in the Exercise Vital Sign were noted in the control group or intervention group at 3 months, 6 months or 1 year of follow-up. At 3 months resistance training activity was reported to increase in the intervention group from 29.1% to 42.8% while unchanged in the control group (26.3% to 31.4%) (p<0.05). The increase in resistance training was driven by a significant increase in those with grip strengths below normative values. Lifestyle physical activity was also reported increased in the intervention group at both 3 months (27.7% to 29.1%) and 6 months (25%) whereas it declined in the control group from 24.4% to 20.1% at 3 months and 18.7% at 6 months(p<0.05). Among the subjects who were less active at baseline (Exercise Vital Sign<150) we observed a significant increase in their Exercise Vital Sign from a baseline of 86 to 146 at 6 months (p<0.05). CONCLUSIONS: Recording the Exercise Vital Sign and providing exercise recommendations appears effective in increasing physical activity in less active individuals. In an already very active population measuring grip strength and estimating VO2max using a step test may have short term positive effects on lifestyle activity and resistance training. Wider adoption of these measures could be effective in promoting physical activity and resistance training.