The invisible benefits of exercise.

OBJECTIVE To examine whether--and why--people underestimate how much they enjoy exercise. DESIGN Across four studies, 279 adults predicted how much they would enjoy exercising, or reported their actual feelings after exercising. MAIN OUTCOME MEASURES Main outcome measures were predicted and actual enjoyment ratings of exercise routines, as well as intention to exercise. RESULTS Participants significantly underestimated how much they would enjoy exercising; this affective forecasting bias emerged consistently for group and individual exercise, and moderate and challenging workouts spanning a wide range of forms, from yoga and Pilates to aerobic exercise and weight training (Studies 1 and 2). We argue that this bias stems largely from forecasting myopia, whereby people place disproportionate weight on the beginning of a workout, which is typically unpleasant. We demonstrate that forecasting myopia can be harnessed (Study 3) or overcome (Study 4), thereby increasing expected enjoyment of exercise. Finally, Study 4 provides evidence for a mediational model, in which improving people's expected enjoyment of exercise leads to increased intention to exercise. CONCLUSION People underestimate how much they enjoy exercise because of a myopic focus on the unpleasant beginning of exercise, but this tendency can be harnessed or overcome, potentially increasing intention to exercise.