Physical health may not be the only benefit of getting regular exercise. A new landmark study has revealed that regular exercise of any intensity can prevent future depression. What is most amazing is that it only requires an hour a week of your time.
“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 (University of New South Wales).
Following participants over years
This study is considered the largest and most extensive study of its kind, consisting of 33,908 Norwegian adults. These individuals were followed for 11 years while having their levels of exercise and symptoms of depression and anxiety evaluated.
Data was gathered from 1984 to 1997 and was taken as part of the health study of Nord-Trøndelag County (HUNT study). Participants were asked about their baseline frequency of exercise and at what intensity they became breathless or sweating, became breathless and sweating, or exhausted themselves. After this, a follow-up questionnaire was completed by each to indicate any emerging anxiety or depression.
To make sure there were no confounding variables, the researchers accounted for several factors that could impact the association between mental illness and exercise. These included socio-economic and demographic factors, substance use, body mass index, new onset physical illness, and perceived social support.
Just one hour a week of exercise is sufficient
The results of the study showed that people who reported they did not perform exercise at all, as their baseline, had a 44 percent increased the chance of developing depression compared to those exercising one to two hours a week. However, it was found that exercise did not carry a protective effect against anxiety.
The researchers concluded that 12 percent of cases of depression in this study could have been prevented if participants undertook just one hour of physical activity each week.
While this study was carried out on Norwegians, Americans are finding themselves in a similar place. According to a CDC, nearly 80 percent of adult Americans do not get the recommended amount of exercise per week. It comes as no surprise that major depression is one of the most common mental disorders in the United States, with an estimated 16.1 million Americans affected by depression as of 2015.
“Most of the mental health benefits of exercise are realized within the first hour undertaken each week. 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,” said Associate Professor Harvey.
Related: Regular yoga may reduce symptoms of depression