Just One Hour Of Exercise Per Week Can Prevent Depression, Research Suggests

Completing just one hour of exercise per week at any intensity could be enough to prevent depression for some patients, new research suggests.

A study led by the Black Dog Institute found that 12% of cases of depression could have been prevented if participants undertook just one hour of physical activity each week.

The landmark study, published in the American Journal of Psychiatry, worked with more than 33,000 Norwegian adults to analyse their levels of exercise and symptoms of depression and anxiety over 11 years.

The researchers concluded that even small amounts of exercise can protect against depression, with mental health benefits seen regardless of age or gender.

Commenting on the findings, lead author associate professor Samuel Harvey from Black Dog Institute and UNSW said:  “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.”

He added that the “findings are exciting” because they show that even relatively small amounts of exercise - from one hour per week - can “deliver significant protection against depression”.

“We are still trying to determine exactly why exercise can have this protective effect, but we believe it is from the combined impact of the various physical and social benefits of physical activity,” he said.

“These results highlight the great potential to integrate exercise into individual mental health plans and broader public health campaigns. 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.”

The findings follow the Black Dog Institute’s recent Exercise Your Mood campaign, which ran throughout September and encouraged the public to improve their physical and mental wellbeing through exercise.

Researchers used data from a healthy cohort of participants who were asked to report the frequency of exercise they participated in and at what intensity: without becoming breathless or sweating, becoming breathless and sweating, or exhausting themselves.

At follow-up stage, they completed a self-report questionnaire to indicate any emerging anxiety or depression.

The research team also accounted for variables which might impact the association between exercise and common mental illness. These include socio-economic and demographic factors, substance use, body mass index, new onset physical illness and perceived social support.

Results showed that people who reported doing no exercise at all at the start of the trial had a 44% increased chance of developing depression compared to those who were exercising one to two hours a week.

However, these benefits did not carry through to protecting against anxiety, with no association identified between level and intensity of exercise and the chances of developing the disorder.

“Most of the mental health benefits of exercise are realised within the first hour undertaken each week,” said associate professor Harvey.

“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.”

Useful websites and helplines:

• Mind, open Monday to Friday, 9am-6pm on 0300 123 3393
• Samaritans offers a listening service which is open 24 hours a day, on 116 123 (UK and ROI - this number is FREE to call and will not appear on your phone bill.)
• Get Connected is a free advice service for people under 25. Call 0808 808 4994 or email: help@getconnected.org.uk