A massive study out of South Korea just delivered a clear message: staying physically active—or becoming more active over time—can significantly reduce your risk of depression.
Published in the Journal of Affective Disorders, the study tracked nearly 4 million adults using national health data found that people who kept up moderate-to-vigorous physical activity or increased it were less likely to develop depression or suffer its symptoms—even if they had a history of it.
The research went further than most previous studies, which often look at physical activity at just one point in time, by studying changes in activity over the years impacted mental health. Using data from South Korea’s National Health Insurance Service, lead author, Yohwan Lim, and his team examined people’s exercise habits from 2014–2017 and followed up on depression diagnoses and symptoms through 2018 and beyond.
Participants self-reported how often they did moderate (like brisk walking or biking) or vigorous (like running) activity, and were grouped as inactive, low (1–2 days/week), moderate (3–4), or high (5+). Their mental health was tracked through medical records and the PHQ-9 depression questionnaire.
The results? More activity consistently meant lower odds of depression, especially among those who had previously been diagnosed. Becoming more active was associated with up to 26% lower odds of another depressive episode. Those active five days a week had up to 40% lower odds of depressive symptoms than those who didn’t exercise.
“Our study highlights the importance of maintaining consistent, moderate-to-vigorous physical activity over time to reduce the risk of depression,” Lim said.
Interestingly, people who were active before being diagnosed with depression and stayed active after saw the most benefit. Interestingly those who were inactive before diagnosis didn’t get as much of a mental health boost even if they started exercising later—at least when it came to future clinical diagnoses. That said, they still showed fewer depressive symptoms, which still matters.
Lim suggests that regular movement might ease depression by reducing stress, improving sleep, encouraging social contact, and boosting brain chemicals that support mood.
Still, with its enormous sample size and multi-year scope, this is one of the most comprehensive studies to date linking physical activity and mental health.
In conclusion, if you care about your mental health or being a mental health advocate in anyway, the only way to show you care is by exercising yourself. Cut the excuses, buy the membership and go. There are also plenty of good online exercise videos on the internet for free.
There is no medicine better than a good moderate to vigorous exercise session in both preventing and treating mental and physical health conditions.
Y Lim. Longitudinal association between consecutive moderate-to-vigorous physical activity and the risk of depression among depressed and non-depressed participants: A nationally representative cohort study. Journal of Affective Disorders (2025). https://doi.org/10.1016/j.jad.2025.03.048
