What is the evidence that physical activity interventions alone, or combined with diet modification or smoking cessation, are effective in helping individuals in the general population change their aerobic physical activity and maintain an active lifestyle?
Overall results at the study level. We did find evidence that it is possible to intervene on subjects to increase their physical activity in a manner that can be at least partly maintained for at least three months after the intervention stopped. However, the majority of the studies we examined did not demonstrate any effect on physical activity at the first followup three months or more after the end of any intervention activities. This does not bode well for the long-term maintenance of physical activity behaviors after the end of interventions as they are currently designed. Of the studies examined, 45 percent demonstrated a positive effect (significance level of less than 0.05) of at least one physical activity outcome from at least one intervention at a followup time point at least three months after the end of interventions. However, the overall magnitude of the effects found was generally modest. Only four of the studies had an effect size greater than 0.5 at followup. In one of
