Dose response between total volume of physical activity and health and fitness

PURPOSE: Studies published in 1990s were evaluated for the possible dose response between the total volume of physical activity and the fitness and health outcomes, and for the characteristics of the dose response relations. METHODS: Nineteen observational studies and 15 randomized trials were identified. The scope of the studies was on primary prevention among inactive, healthy, middle-aged and elderly men and women. MET-min x wk(-1) was used as the primary volume measure. No studies addressing specifically the volume-outcome dose response were identified. RESULTS: The cross-sectional and follow-up studies suggested a graded dose response of the volume of physical activity with all-cause mortality, stroke and several coronary heart disease risk factors. The benefits were apparent among both men and women. Nonrandomized and uncontrolled randomized trials exhibited no clear dose response relationship, whereas the randomized controlled trials showed a crude graded dose response between the exercise volume as measured by MET-min x wk(-1) and VO(2max) but not between volume and disease risk factors. An apparently clearer dose response was seen between the intensity of physical activity and the VO(2max) response. These data do not allow for quantitative characterization of the observed dose response relations between physical activity volume and health and fitness. CONCLUSION: Fairly strong evidence indicates a crude dose response between the total volume of weekly physical activity and cardiorespiratory fitness but only weak evidence for a dose response of activity volume and health measurers.