Responses to exercise in children with sickle cell trait.

To determine whether responses to exercise in children with sickle cell trait (AS) are different from those of normal children, we performed dynamic cycle ergometer stress testing in 48 children with AS, aged 4 to 21 years. We compared these data with those obtained from 184 healthy black children. No subject with AS demonstrated definite ischemia on the exercise ECG, but four (8.3%) had equivocal ischemia. Population statistics derived from Z score values showed that the subjects with AS had lower exercise values for heart rate and work load than the controls. The BP response to exercise was normal in subjects with AS. Since no ischemia or complications occurred, exercise in subjects with AS appears to be safe. Further studies are needed to define the mechanism for the impaired pulse rate and work load variables.