Depression: a crippling illness characterized by fatigue, feelings of worthlessness, and a depressed state that affects 350 million people worldwide. This overwhelming statistic reminds us that any one of us could develop the condition—but not a single one of us hopes to. So we do what we can to prevent onset, like getting proper sleep, eating healthy foods, exercising, and pursuing our passions. But we have to wonder, do these preventative measures really work? As far as exercising goes, a new study “Exercise and the Prevention of Depression: Result of the HUNT Cohort Study” led by the Black Dog Institute says absolutely—even if you exercise for just an hour per week.

This study, which was published in the American Journal of Psychiatry, found that even small amounts and intensities of exercise can prevent the development of depression, regardless of age and gender. To make this discovery, the research team analyzed levels of exercise and symptoms of depression and anxiety in over 33,000 Norwegian adults for 11 years. The participants in this study were first asked to report how often they exercise and at what intensity. And then at follow-up, they answered a questionnaire used to gage emerging anxiety or depression.

After first accounting for variables that might affect the correlation between exercise and mental illness—such as demographic factors, substance use, and body mass index—the team found that people who did not exercise at all had a 44% increased chance of developing depression or depressive symptoms, as opposed to those who exercised for just one or two hours each week. The team also found that at least 12% of these depression developments could have been prevented, had the individuals been active for just one hour a week.

“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,” explains lead author and associate professor Samuel Harvey from Black Dog Institute and UNSW. “These findings are exciting because they show that even relatively small amounts of exercise—from one hour per week—can deliver significant protection against depression,” he continues.

While the researchers haven’t discovered exactly why exercise is so beneficial to mental health, they’re excited about the clear evidence that it is indeed a protector against depression and hope to utilize their finding to motivate others to get moving. “These results highlight the great potential to integrate exercise into individual mental health plans and broader health campaigns,” says Harvey. “If we can find ways to increase the population’s level of physical activity even by a small amount, then this is likely to bring substantial physical and mental health benefits.”

Multiple treatment methods prove effective in treating depression, such as psychotherapy and medication, which help individuals better deal with their illness. But this study proves that scientists and researchers aren’t settling—they’re after preventative measures so that people never have to experience depression’s crippling effects. And so far, it appears that they’re on the right track.

Source: University of New South Wales “One Hour of Exercise a Week Can Prevent Depression.” NeuroscienceNews. NeuroscienceNews, 3 October 2017. <>.

Original Research: Abstract for “Exercise and the Prevention of Depression: Results of the HUNT Cohort Study” by Samuel B. Harvey, F.R.A.N.Z.C.P., Ph.D., Simon Øverland, Ph.D., Stephani L. Hatch, Ph.D., Simon Wessely, F.R.C.Psych., M.D., Arnstein Mykletun, Ph.D., and Matthew Hotopf, F.R.C.Psych., Ph.D. in American Journal of Psychiatry. Published online October 3 2017 doi:10.1176/appi.ajp.2017.16111223