Small Lifestyle Changes, Big Mental Health Benefits: Exercise's Role in Preventing Depression

Even small amounts of exercise – from as little as one hour per week – can offer significant protection against depression, an international research team led by the UNSW Sydney and Black Dog Institute has found.

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.

Study Results: Exercise and Depression

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

Extensive Analysis: Exercise and Mental Health

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.

Preventative Potential: Physical Activity and Depression

“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.

Exciting Findings: Impact of Exercise on Depression

“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.

Integration into Mental Health Plans

“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.

Public Health Implications: Promoting Exercise

“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.”

Following Research: Exercise Your Mood Campaign

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.

Data Source: Health Study of Nord-Trøndelag County

Researchers used data from the Health Study of Nord-Trøndelag 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.

Addressing Sedentary Lifestyles: Importance of Exercise

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.

Accounting for Variables: Exercise and Mental Illness

The research team also accounted for variables which might impact the association between exercise and common mental illness.

Impact on Depression: Association with Exercise

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.

Lack of Association with Anxiety

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.

Addressing Physical Inactivity: Australian Statistics

According to the Australian Health Survey, 20% 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.

Rapid Mental Health Benefits: First Hour of Exercise

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

Collaborative Study Efforts

The study involved researchers from Black Dog Institute, King’s College London, UNSW Sydney, Norwegian Institute of Public Health, University of Bergen (Norway), Nordland Hospital Trust (Norway) and the Arctic University of Norway.

Collaborative Research Endeavor: HUNT Study

The HUNT Study is a collaboration between the HUNT Research Centre, Norwegian University of Science and Technology, Norwegian Institute of Public Health and Nord-Trøndelag County Council.