Study reveals the mental health benefits of regular physical activity

Embargoed until Monday, November 01, 2010

Crucially, researchers have also found that this activity needs to be taken in people’s leisure time if they are to feel the benefits. The study showed that people who exert themselves at work, by doing lots of walking or lifting, are no less likely to be depressed than people with sedentary jobs.

Researchers from the Institute of Psychiatry, King’s College London teamed up with academics from the Norwegian Institute of Public Health and the University of Bergen in Norway to conduct the study. They asked 40,401 Norwegian residents how often they engaged in both light and intense physical activity during their leisure time. Light activity was defined as an activity that did not lead to being sweaty or out-of-breath, while intense activity did result in sweating or breathlessness. The residents were also asked how physically active they were at work, underwent a physical examination and answered questions regarding symptoms of depression and anxiety.

The team found an inverse relationship between the amount of leisure-time activity and symptoms of depression. In other words, the more people engaged in physical activity during their spare time, the less likely they were to be depressed. People who were not active in their leisure time were almost twice as likely to have symptoms of depression compared to the most active individuals. Interestingly, the intensity of the exercise didn’t seem to make any difference. Even people who took light exercise, without breaking into a sweat or getting out-of-breath, were less likely to show symptoms of depression.

However, the researchers found no such relationship between workplace activity and symptoms of depression. Nor did they find any consistent relationship between physical activity and anxiety.

Lead researcher Dr Samuel Harvey said: “Our study shows that people who engage in regular leisure-time activity of any intensity are less likely to have symptoms of depression. We also found that the context in which activity takes place is vital and that the social benefits associated with exercise, like increased numbers of friends and social support, are more important in understanding how exercise may be linked to improved mental health than any biological markers of fitness. This may explain why leisure activity appears to have benefits not seen with physical activity undertaken as part of a working day.”

References:

Harvey SB, Hotopf M, Øverland S and Mykletun A (2010) Physical activity and common mental health, British Journal of Psychiatry, 197: 357-364