An hour of exercise a week can kill depression.

ISLAMABAD -- Researchers have found that just one hour of exercise every week can help prevent depression.

The results, published in the American Journal of Psychiatry, showed that people of all ages can gain mental health benefits from even small amounts of exercise.

The analysis involved 33,908 Norwegian adults who had their levels of exercise and symptoms of depression and anxiety monitored over 11 years.

The team found that 12 per cent of cases of depression could have been prevented if participants undertook just one hour of physical activity 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...