The effects of exercise on children with attention-deficit hyperactivity disorder

The effects of exercise on children with attention-deficit hyperactivity disorder (ADHD) were evaluated by studying the rate of spontaneous eye blinks, the acoustic startle eye blink response (ASER), and motor impersistence among 8- to 12-yr-old children (10 boys and 8 girls) meeting DSM-III-R criteria for ADHD. Children ceased methylphenidate medication 24 h before and during each of three daily conditions separated by 24-48 h. After a maximal treadmill walking test to determine cardiorespiratory fitness (VO(2peak)), each child was randomly assigned to counterbalanced conditions of treadmill walking at an intensity of 65-75% VO(2peak) or quiet rest. Responses were compared with a group of control participants (11 boys and 14 girls) equated with the ADHD group on several key variables. Boys with ADHD had increased spontaneous blink rate, decreased ASER latency, and decreased motor impersistence after maximal exercise. Girls with ADHD had increased ASER amplitude and decreased ASER latency after submaximal exercise. The findings suggest an interaction between sex and exercise intensity that is not explained by physical fitness, activity history, or selected personality attributes. The clinical meaning of the eye blink results is not clear, as improvements in motor impersistence occurred only for boys after maximal exercise. Nonetheless, these preliminary findings are sufficiently positive to encourage additional study to determine whether a session of vigorous exercise has efficacy as a dopaminergic adjuvant in the management of behavioral features of ADHD.