Abstract
Despite the myriad benefits associated with regular physical activity (PA), few American adults accrue sufficient weekly PA. Although "lack of time" is often cited as a correlate of physical inactivity, a growing body of evidence suggests that, perhaps more importantly, people allocate their leisure-time to activities they find more enjoyable than PA. These findings underscore the need to devise physical activities that will be chosen over other enjoyable, but less healthy, behavioral alternatives. As a first step in this direction, we designed a group social PA play program for adults, known as PlayFit. The overarching philosophy of PlayFit is that fun and enjoyment are among the most important influences on PA adherence. In PlayFit, traditional sport games are modified to fulfill basic psychological needs, in a non-competitive, and non-contact environment. We will randomize 280 sedentary adults 18-50 years of age to 12-months of PlayFit or traditional group exercise, matching the groups on intensity, frequency, and duration. The primary outcomes include cardiorespiratory fitness (VO(2peak)), group adherence, and group enjoyment. We hypothesize that, at 6 months, cardiorespiratory fitness will have increased to the same extent in both groups, but at 12 months, only those randomized to PlayFit will have maintained their fitness through better adherence than Group Exercise - and this outcome will be mediated by enjoyment of the assigned group. Findings from this study could provide evidence that a focus on providing fun and enjoyable PA experiences for adults may be a viable route toward improving PA adherence. A simple, inexpensive PA intervention, such as PlayFit, may represent one such approach to do so.