A study published in the American Journal of Psychiatry on October 3, 2017 revealed even small amounts of exercise can protect against clinical depression.

The Exercise and the Prevention of Depression study led by the Black Dog Institute, utilised data from the Health Study of Nord-Trøndelag County (HUNT study) –one of the most comprehensive population-based health surveys ever performed.

Researchers examined a group of 33,908 adults who presented with no symptoms of common mental health disorders, and monitored their levels of exercise versus symptoms of clinical depression and anxiety over 11-years.

The researchers determined that engagement in regular exercise, regardless of intensity, reduced the incidence of future depression. Moreover, undertaking just one hour of physical activity each week was shown to prevent 12 per cent of cases of clinical depression.

The participants who did not engage in any physical activity at study commencement were 44 per cent more likely to become depressed compared with those who exercised for at least one-to-two hours per week.

The researchers found no link between the levels and intensity of exercise and chance of developing anxiety.

“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 Associate Professor Samuel Harvey from the Black Dog Institute, Randwick, NSW.

“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,” A/Prof Harvey 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.”

With sedentary lifestyles on the rise, Australia’s growing incidence of clinical depression comes as no surprise.

This new data is important because it demonstrates the significant benefit of incremental exercise on mental health, and should hopefully encourage Australians to invest more effort into protecting their overall health and well being.