Physical exercise, like diet, and mood are complicated bio-psycho-social functions that are depended on dozens of overlapping factors in each person. Most meta-

Physical exercise, like diet, and mood are complicated bio-psycho-social functions that are depended on dozens of overlapping factors in each person. Most meta-analyses and their underlying studies ignore most of these dimensions and come to a binary yes-no conclusion based on a mere p-value. Huge confounding effects persist that the studies should heavily take into account. At least examining such popular functions provide large samples cheaply.