Researchers suggest an hour of exercise a week can help prevent future cases of depression according to a new Australian study published in the American Journal of Psychiatry. The paper followed 22,000 healthy Norwegian adults with no displayed signs of depression or anxiety for 11 years.

The participants were asked about their exercise habits and symptoms of depression and anxiety in the beginning and end of the study, they also controlled other potential factors, including age, gender, social support, smoking, drinking and body mass index.

At the start around 12% said they did not exercise while the rest said they exercised “up to 30 minutes” to “more than 4 hours” a week.

Over the 10 years of the study starting about 7% of the people developed depression and around 9% developed anxiety. Researchers found there was no link between exercise and anxiety, but there was a link between exercise and depression.

Those who said they didn’t exercise at the beginning of the study were 44% more likely to become depressed, compared to those who exercised for one to two hours a week.
Researchers couldn’t prove a cause-and-effect relationship between exercise and the risk depression, but they did strongly suggest one.

If their hypothesis is correct 12% of depression cases could be prevented if people exercised for one hour a week. The exercise also didn’t need to be anything extreme and they found people benefited from any type of exercise.

“Given that the intensity of exercise does not appear to be important,” the writers in the paper wrote according to TIME, “it may be that the most effective public health measures are those that encourage and facilitate increased levels of everyday activities, such as walking or cycling.”
The researchers wrote that combined physical and social benefits of exercise help prevent depression and that the exercise helps with self-esteem.