For those of us seeking even more science to convince us to get off the couch and exercise, here it is: moving for just an hour or two per week could help prevent future depression, according to a large new study published in the American Journal of Psychiatry.
Researchers from institutions including King’s College London and the University of New South Wales looked at data from 33,908 Norwegian adults that spanned 11 years. (The data came from an existing study called the Health Study of Nord Trøndelag County).
Participants reported their baseline exercise habits—including how intense their workouts were—and filled out questionnaires about their mental health. After accounting for factors like substance use, socioeconomic and demographic information, body mass index and how much social support participants felt they had, the researchers found that people who didn’t exercise at all at the beginning of the study were 44 percent more likely to develop depression compared to people who moved for just an hour or two per week, according to the press release.
“Our models suggested that as much as 12 percent of the new cases of depression may have been avoided if the whole population undertook just 1 or 2 hours of physical activity each week,” lead author Samuel Harvey, PhD, who leads the Workplace Mental Health Research Institute at Black Dog Institute (a mental health-focused research institution) told Thrive Global via email.
“The benefits remain the same after the first hour of exercise, but it seems to be the movement from doing nothing to doing one or two hours a week is where the big benefits occur,” Harvey said via email. And if you’re wondering whether staving off future symptoms of depression means you have to become an avid CrossFit enthusiast, don’t fear: any type of movement, no matter how intense, seems to make a difference. “That was one of the interesting things,” Harvey wrote over email “It didn’t seem to matter how intensive the exercise was, the mental health benefits were the same.”
“We’ve known for some time that exercise has a role to play in treating symptoms of depression, but this is the first time we have been able to quantify the preventative potential of physical activity in terms of reducing future levels of depression,” Harvey said in the press release.
Depression is a big problem, to put it mildly: the World Health Organization estimates that more than 300 million people worldwide live with depression. And while we know that movement is good for us, the new research shows that just a bit of activity can work as a buffer against undesirable mental health outcomes.
The researchers think exercise is a boon to your mental health because of the combination of physical and social benefits it brings. Harvey wrote over email that the social benefits might be particularly powerful. “Spending time with other people, doing something you enjoy, feeling a sense of control or accomplishment, may be as or more important” than the “biological effects of exercise, such as changes in the brain chemistry,” he wrote.
It’s interesting to note that the depression-related benefits of exercise in this study didn’t hold true for symptoms of anxiety. “Depression and anxiety are different disorders, but are very closely linked,” Harvey wrote over email. “I think the fact that exercise has an impact on the future risk of depression, but not anxiety, suggests that this effect is not just about a general enhancement of wellbeing, but is related to something specific about depression.”
This research could have huge real world applications, namely in shaping public health campaigns to help get people moving and, in the process, improve their future mental health.
“With sedentary lifestyles becoming the norm worldwide, and rates of depression growing, these results are particularly pertinent as they highlight that even small lifestyle changes can reap significant mental health benefits,” Harvey said in the press release.
This isn’t to say that doing more than one hour of exercise isn’t important for your health (after all, the National Institutes of Health recommends that adults get a minimum of 150 minutes of moderate-intensity aerobic exercise, or 75 minutes of high-intensity exercise, per week). But this research is evidence that, in terms of boosting your mental well-being, it might take less moving around than you’d think to keep yourself well.
Read the study here.