Physical aptitude of sickle cell trait subjects

In order to obtain informations about the exercise capacity, the functional tolerance and the cardiorespiratory response to exercise of sickle cell trait subjects (HbAS) compared to those of normal subjects (HbAA), two groups of six male adults formed into pairs HbAS-HbAA have performed a triangular Exercise Test (corresponding to a gradually maximal exercise of average duration) and a Square-Wave Endurance Exercise Test (SWEET 45 corresponding to a severe exercise of long duration) after an interval of 24 h. The exercise capacity of HbAS was equal to that of normal subjects and their functional tolerance of performed exercises was good. The cardiorespiratory response of the two groups was identical for the gradually maximal exercise of average duration. But it was different for the severe exercise of long duration. During this type of exercise, the ventilation (V ̇E l. min-1) and heart rate (HR b. min-1) of HbAS subjects were more important than those of normal subjects whereas their oxygen uptake (V ̇O2 ml. kg-1. min-1) was weaker. These results suggest that the physical fitness of HbAS is normal in regard to V ̇O2 max but it is limited in regard to endurance because of a decrease of their oxygen transport related to their hemoglobinopathy. © 1987 Editions Scientifiques Elsevier.