A new study that more than 1.2 million people participated in suggests that exercise can indeed boost your mood and that some types may be better than others.
It's long been thought that exercise can make you feel better, both physically and mentally, with quite a bit of research showing a beneficial effect on depression.
Now, one of the largest studies of its kind confirms that just about any exercise can help improve your mood compared with doing nothing at all, and some types may be more effective than others.
Overall, people reported having an average of 3.5 days of poor mental health in any given month, according to the report published in the Lancet Psychiatry.
Just about any exercise — including walking or housework — helped reduce that number by an average of 1.5 days a month, or 43%. Team sports, cycling, and aerobic and gym exercises had the biggest effect, reducing poor mental health days by about 20%. Walking, on the other hand, was linked to a 10% reduction.
People who worked out for 30 to 60 minutes at a time, three to five days a week, seemed to get the most benefits, compared with those who exercised either less or more. In fact, people who exercised 23 times a month, or for longer than 90 minutes per session, had worse mental health than those who exercised less often or for shorter periods of time, the authors noted.
Overall, 45 minutes was better than less time, and there was no benefit in working out more than an hour.
"It's not like everyone has to go and run a marathon, and actually running wasn’t even the most effective," the study's senior investigator, Adam Chekroud, told BuzzFeed News. "Things like yoga, things like walking, even household chores, seemed to have some benefit over doing nothing at all."
The effect was stronger for people who said they had been diagnosed with depression. Among that group, those who exercised reported 7.1 days a month during which their mental health was "not good," compared with 10.9 days reported by those who did not exercise.
Chekroud, an assistant professor of psychiatry at Yale University, and his colleagues analyzed data from the Centers for Disease Control and Prevention Behavioral Risk Factors Surveillance System, a big telephone survey that's conducted each year. In this case, the surveys were from 2011, 2013, and 2015.
The study found that team sports were the best for your mood. TBH, the effect here might not be from the exercise, but from the team camaraderie.
So team sports were supposedly the number one best way to reduce the number of days people felt bad every month. But that could be due to factors other than just the exercise itself, Chekroud said.
"If the benefit of team sports was just the running, then we should see that team sports and running have the same impact on mental health — but they don’t," Chekroud said. "It seems like there is this additional benefit."
The structure and social interaction of team sports — if they are your thing —might offer additional mental health benefits that the activity of exercise may not give you, he said.
So why is exercise so good for mental health?
Exercise is probably good for your mood for a number of reasons, Chekroud said. One is neurobiological, with some research suggesting that exercise can boost brain-derived neurotrophic factor (BDNF) — a nerve growth factor that may play a role in mood — and other compounds.
Exercise can also be about social interaction and "putting structure into your life — it’s probably making you tired, it’s probably making you sleep better, and so it’s a pretty holistic approach for tackling a number of different things," he said.
Of course, people who feel good may be more likely to exercise, so it can be difficult from this type of study to determine which came first — the good mood or the exercise.
However, past randomized controlled studies, in which some people are assigned to exercise and others are not, do suggest that starting to work out can actually improve mood.
And of course, exercise is not going to work for everyone all of the time. Mental health is complicated, and lots of different factors can affect any given person's mood on any given day — including financial and societal factors outside their control.
Exercise is "an important tool that we have for improving mental health, but it’s by no means the only one," Chekroud said. "I would encourage people to seek out the opinion of a doctor and make sure you are thinking about things like medication, counseling, and psychotherapy."
Chekroud is also the cofounder of Spring Health, a platform he is marketing to corporations to help improve employee mental health. Several of the study's co-authors are advisers to Spring Health, and Microsoft, which provided the computing resources for the study, is an investor in the platform. The funding agencies were not involved in the data analysis and publication of the results, Chekroud said.
An earlier version of this post misstated the name of Chekroud's platform, which is called Spring Health, not Spring.