One hour of exercise a week can prevent depression

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A landmark study led by the Black Dog Institute has revealed that regular exercise of any intensity can prevent future depression - and just one hour can help.

Published today in the American Journal of Psychiatry, the results show even small amounts of exercise can protect against depression, with mental benefits seen regardless of age or gender.

In the largest and most extensive study of its kind, the analysis involved 33,908 Norwegian adults who had their levels of exercise and symptoms of depression and anxiety monitored over 11 years.

The international research team found that 12 percent of cases of depression could have been prevented if participants undertook just one hour of each 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," said lead author 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.

"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.

"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 Australians to improve their physical and mental wellbeing through exercise.

Researchers used data from the Health Study of Nord-Tr√łndelag County (HUNT study) - one of the largest and most comprehensive population-based health surveys ever undertaken - which was conducted between January 1984 and June 1997.

A healthy cohort of participants was asked at baseline 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 (the Hospital Anxiety and Depression Scale) 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 baseline 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.

According to the Australian Health Survey, 20 percent of Australian adults do not undertake any regular physical activity, and more than a third spend less than 1.5 hours per week being physically active. At the same time, around 1 million Australians have depression, with one in five Australians aged 16-85 experiencing a mental illness in any year.

"Most of the mental health benefits of are realised within the first hour undertaken each week," said Associate Professor Harvey.

"With sedentary lifestyles becoming the norm worldwide, and rates of growing, these results are particularly pertinent as they highlight that even small lifestyle changes can reap significant mental health benefits."


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Journal information: American Journal of Psychiatry

Citation: One hour of exercise a week can prevent depression (2017, October 3) retrieved 23 April 2019 from https://medicalxpress.com/news/2017-10-hour-week-depression.html
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Oct 03, 2017
Well duh. Behaving as we did during the Pleistocene is what our bodies evolved to expect. If we are sedentary then our bodies think we are sick, and the immune system starts looking for something to cure. Inflammation and metabolic disease ensue.

But re the article, people in Norway are supposed to be depressed. Hence the beautiful and haunting music they produce.
https://youtu.be/48Z2h1pNytg

Oct 04, 2017
Step it up to four hours and you can get jacked! ;P

Norway, do you even lift bro?

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