Exercise and Depression from Scientific American:
A 2013 review by the nonprofit organization Cochrane, regarded as a leader in evidence based medicine, concluded that exercise is just as effective a treatment for depression as medication and counseling. A recent meta-analysis, published in 2016, echoes Cochrane’s finding. A team of international researchers examined 25 of the most rigorous experiments and determined that exercise, especially moderate to vigorous aerobic exercise under professional supervision, is indeed a potent treatment for depression. When they adjusted their analysis to account for weak studies—those most prone to some kind of experimental bias—they found an even stronger effect, suggesting that some previous meta-analyses may have underestimated exercise’s benefits for mental health. The researchers further calculated that it would take at least 1,000 contradictory studies to negate the affirming evidence that has piled up so far. Yet another review computed that when exercise is used to treat depression, success rates increase by as much as 67 to 74 percent.