Depression is a very serious health issue, and there is often no easy way to push back against it. But a huge new study shows compelling evidence that even moderate exercise can be good at counteracting symptoms related to depression.

Researchers first went to the UK Biobank, which houses the genetic and health info of nearly 400,000 men and women. Then they used Mendelian randomization. What is that? Here’s how the article describes it:

With Mendelian randomization, scientists zero in on small snippets of genes that vary from person to person. These variants are passed out before birth and do not change afterward; they are not altered by upbringing. Thanks to large-scale genetics studies, scientists have associated many of these snippets with specific health behaviors and risks. People with certain gene variants are, for example, more likely to overeat or be physically active than people without that variant.

This allowed them to connect people who were genetically predisposed to exercise to lower rates of depression and vice-versa. But more importantly, again from the article:

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. Less-taxing activities like fast walking, housework and so on also afforded protection against depression, but it took about an hour a day to have an effect.

We view a macro study using mathematical randomization as simply one data point and not a definitive rule or law. We’re also aware of fascinating new techniques to battle depression including TMS (trans cranial magnetic stimulation) and ketamine infusions – which help patients move away from drug therapy. The nice thing about exercise? It has the fewest side effects of any of these methods to fight depression.

-Shane M.