About 6 percent of American adults report symptoms consistent with attention deficit hyperactivity disorder, or ADHD, which leads to anxiety, depression, low energy and motivation, poor performance at work or school and also increased traffic accidents.

University of Georgia researchers performed an experiment in which they had 32 young men with elevated ADHD symptoms cycle at a moderate intensity for 20 minutes on one day, and on another day sat and rested for 20 minutes as a control condition.

The participants were asked to perform a task requiring focus both before and after the different conditions, and researchers noted leg movement, mood, attention and self-reported motivation to perform the task.

The study showed that it was only after the exercise when the participants felt motivated to do the task; they also felt less confused and fatigued and instead felt more energetic. Interestingly, leg movements and performance on the task did not change after the exercise--rather, the exercise helped the young men feel better about doing the task.

These results suggest that young men who have symptoms of ADHD can benefit psychologically from the short workouts, similar to the benefits enjoyed by typical adults who work out, say the researchers of their study, which appears in Medicine & Science in Sports & Exercise.

"Exercise is already known as a stress reducer and mood booster, so it really has the potential to help those suffering with ADHD symptoms," says Patrick O'Connor, a University of Georgia professor and the study’s lead author. "And while prescription drugs can be used to treat these symptoms, there's an increased risk of abuse or dependence and negative side effects. Those risks don't exist with exercise, he adds.