Exercise Responses in Boys With Attention Deficit/Hyperactivity Disorder

OBJECTIVE: The effect of stimulant medication on exercise responses was studied in 14 boys (10.9 +/- 1.1 years) with attention deficit/hyperactivity disorder (ADHD). METHOD: Exercise, with and without medication, was performed at 25 W, 50 W, and 75 W, followed by a peak exercise test. RESULT: Submaximal heart rate (HR) was significantly higher by ~8 to 13 b.min(-1) across the three intensities during the medication trial, but oxygen uptake (VO(2)), respiratory exchange ratio (RER), and perceived exertion were similar (p > .05). At peak exercise, VO(2), HR, and work rate were attenuated (p < or = .05) in the absence of medication but not RER or perceived exertion. The decreased peak exercise responses were apparent in 6 of 13 participants. CONCLUSION: Stimulant medication raises submaximal HR but does not affect other cardiorespiratory measures or perceived exertion. Without medication physiological responses at peak exercise are attenuated in some but not all boys with ADHD.