But those past studies showed only that exercise and depression are linked, not that exercise actually causes a drop in depression risk. PHYSICAL ACTIVITYThat result is what Choi and her colleagues found when they applied Mendelian randomisation to exercise and depression. Delving deeper, the scientists found that, statistically, the ideal amount of exercise to prevent depression started at about 15 minutes a day of running or other strenuous exercise. This time they looked for gene variants related to depression and whether people who carried those variants and a propensity for depression tended to be physically inactive. So, the researchers concluded, physical activity in this analysis lowered the risk for depression, but depression did not affect whether people exercised.

Source: Daily Nation February 20, 2019 08:48 UTC