Could the perception of fitness account for many of the mental and physical health benefits of exercise?

There is a great amount of professional confidence among researchers and clinicians alike that exercise improves both mental and physical health functioning. Interestingly, until recently, investigators had not seriously examined the possibility that some of the positive emotional results associated with exercise may occur because of psychological gains from the experience of trying to get fit or believing that one is fit rather than from an increase in aerobic physical fitness. Further, some research suggests that the perception of fitness is more closely associated with improvements in physical functioning than is aerobic physical fitness. Perhaps we have underestimated the role of our health beliefs as a useful intervention with or without resulting behavior change. Perhaps, for some health outcomes, it may be more healthful to think that you are fit than actually be fit.