Children who regularly engage in moderate to vigorous physical activity — the type that leaves them sweaty and out of breath — are less likely to develop depression, according to a new study by researchers at the Norwegian University of Science and Technology (NTNU) and NTNU Social Research.

“Being active, getting sweaty and roughhousing offer more than just physical health benefits. They also protect against depression,” said first author Tonje Zahl, a Ph.D. candidate at NTNU.

Although previous studies have found a link between physical activity and a lower risk for depression in adults and young people, the same effect has not been studied in children until now.

For the new study, published in the journal Pediatrics, the researchers followed hundreds of children over four years to see if they could find a correlation between physical activity and symptoms of depression.

They examined just under 800 children when they were six years old, and conducted follow-up examinations with about 700 of them when they were eight and ten years old. Physical activity was gauged with accelerometers, which served as a type of advanced pedometer, and parents were asked about their children’s mental health.

The findings showed that physically active six- and eight-year-olds showed fewer depressive symptoms when they were examined two years later, suggesting that physical activity may protect against the development of depression.

“This is important to know, because it may suggest that physical activity can be used to prevent and treat depression already in childhood,” said Dr. Silje Steinsbekk, associate professor in NTNU’s Department of Psychology. “We also studied whether children who have symptoms of depression are less physically active over time, but didn’t find that to be the case.”

Steinsbekk emphasizes that these results should now be tested in randomized studies where researchers can increase children’s physical activity and then examine any potential link to lowered depression.

Previous findings in adolescents and adults have shown that sedentary lifestyles — like watching television and computer gaming — are associated with depression, but the NTNU children’s study found no correlation between depression and a sedentary lifestyle. Furthermore, depressive symptoms did not lead to greater inactivity.

The takeaway message to parents and health professionals is to be proactive in facilitating physical activity among children, which means allowing and encouraging children to get a little sweaty and breathless.

According to the findings, limiting children’s TV or iPad screen time is not enough — go for a bike ride or engage in outdoor play. Children need actual increased physical activity to reap the mental health benefits.