Just one 20 minute session of physical activity per week can improve mental health, according to a study published online this month in the British Journal of Sports Medicine. 

The study, done by researchers at University College London and based on a health survey of 19,842 men and women in Scotland, found that the mental health benefits increased with longer and more intense physical activity. 

Housework, gardening, and walking were among the activities found to be beneficial, with sports being found most effective in boosting mental health. (Read the study abstract.) 

To produce beneficial results the activity should last at least 20 minutes and make you feel at least slightly breathless, researchers said. 

“Although as little as 20 minutes of physical activity might provide some benefit, those individuals that were physically active every day had the lowest risks of mental and physical ill health,” said Mark Hamer, PhD, University College London researcher and co-author of the study. 

“Therefore, I’d recommend to stick to current guidelines that suggest at least 30 minutes of moderate to vigorous activity five times per week.” (Source: WebMD) 

More and more doctors are prescribing exercise for depressed patients, according to a recent report by the Mental Health Foundation in the UK. 

Twenty-two per cent of the 200 surveyed English GPs recommended exercise for patients who are mildly to moderately depressed, up from only five percent in a comparable study three years ago. 

Sixty-one per cent of the GPs considered exercise to be ‘very effective’ or ‘quite effective’ treatment for these patients, compared with 41 per cent three years ago. 

Exactly how exercise fights depression is still being studied. Research suggests that exercise may stimulate the release of mood-boosting endorphins and neurotransmitters in the brain. 

Psychiatrist and Harvard professor John Ratey, author of Spark: The Revolutionary New Science of Exercise and the Brain calls exercise “Miracle-Gro for the brain.” Quoted in the Los Angeles Times, he said, “Even moving a little bit, such as walking very slowly, causes some increase in heart rate, and it does help. If you’re going to do one, limit the volume and increase the intensity… Intensity is important for the benefits to the brain. Most of the studies showing the benefit of exercise on depression were of people doing brisk walking. That might be at 65 per cent to 75 per cent of maximum heart rate. But that really is the level where you’re just beginning to get a benefit.” 

Ratey emphasized consulting with a doctor first if you are depressed. 

“Exercise improves cognitive behavioral therapy and it’s a good partner to antidepressant and anti-anxiety medications,” he said. 

Benefits of exercise for people with depression