A new small study serves as a reminder that breaking a sweat is a drug-free way to improve mood and alleviate symptoms of health issues like ADHD and depression.

In the report, published in the journal Medicine & Science in Sports & Exercise, researchers assessed 32 adult men who reported having symptoms of ADHD. (Of those 32, two had an official diagnosis from a psychiatrist.) The researchers measured the men’s ability to pay attention, their motivation to perform mental tasks, leg hyperactivity, and their mood before and after they either sat or biked for 20 minutes. The researchers thought that perhaps exercise would behave similarly in the brain as stimulant medications frequently taken by people with ADHD.

“There is very strong and consistent evidence that a single short, moderate-intensity bout of exercise is associated with increased feelings of energy, so if people need a reason to work out, the energy boost with exercise is a worthwhile one,” says study author Patrick J. O’Connor, Ph.D., of the Department of Kinesiology at the University of Georgia, Athens, Georgia.

Exercising, the study authors report, did enhance motivation and overall energy levels. The men also reported fewer feelings of fatigue, depression and confusion after they exercised. It didn’t have an effect on cognitive abilities or levels of hyperactivity, but the study authors found that exercise also didn’t increase feelings of hyperactivity either. The researchers say their findings encourage more research on non-pharmaceutical ways to improve ADHD symptoms.

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