Running is cheaper than therapy,” as the popular Instagram saying goes, but beyond the anecdotal evidence, there’s a robust body of research backing the benefits of exercise, in any form, for mental health.
“We can definitely say that exercise can reduce the risk of someone developing depression. The evidence is quite strong,” says Dr. Felipe Barreto Schuch, adjunct professor and head of the department of methods and sports techniques at Federal University of Santa Maria in Brazil.
The reduction in risk is about 20 per cent, Dr. Schuch says, who recently co-authored a review of research on exercise and depression published in the August 2019 issue of Current Sports Medicine Reports.
Researchers are still trying to understand how exercise exerts its positive effect on mood and mental health. It’s likely that multiple mechanisms are at play. For instance, exercise is thought to increase serotonin, the neurotransmitter linked with feelings of happiness. In addition, physical activity commonly helps people sleep better, which is significant since insomnia sufferers are 10 times more likely than regular sleepers to have clinical depression.
More recently, in a study led by Dr. Jacob Meyer, assistant professor of kinesiology and director of the Wellbeing and Exercise Laboratory at Iowa State University, researchers noted a new link: After exercising, their subjects showed an increase in endocannabinoids (cannabis-like molecules made by the body) as well as a boost in mood.
Published in the September 2019 issue of the journal Medicine & Science in Sports & Exercise, the study observed it doesn’t take an arduous or long workout to reap feel-good benefits. The participants – a small sample size of 17 women with depression – showed an increase in endocannabinoids after completing 30 moderately intense minutes on a stationary bike.
Understanding how exercise interacts with our endocannabinoid system, which is involved in a variety of functions including processing moods, metabolism and the immune system, is a step toward developing new treatment options for depression that include physical activity, Dr. Meyer says.
There is a body of existing research suggesting that exercise is effective therapy for depression and may work as well as other treatments, including antidepressant medications. In a study published in the September 2007 issue of Psychosomatic Medicine, researchers assigned more than 200 adults diagnosed with major depressive disorder to either exercise (home-based or supervised in a group), antidepressants or a placebo pill.
After four months, 45 per cent of those doing supervised exercise, 40 per cent of those doing home-based exercise and 47 per cent of those taking medication experienced remission, meaning they no longer met the criteria for depression. Researchers concluded that the efficacy of exercise seemed generally comparable with receiving antidepressant medication and both fared better than the placebo.
Exercise is not a panacea for depression, however, neither is drug therapy. “The overall picture is that it’s really hard to treat depression. Antidepressant medications are likely one piece of how to successfully do that for lots of people, but the ones we currently have are certainly not a cure-all,” Dr. Meyer says. “When you’re looking at a specific drug, often it’s targeting a specific system or specific receptor in a single way. It’s unlikely to target the multifaceted nature of depression.”