Insufficient ventilation as a cause of impaired pulmonary gas exchange during submaximal exercise

Abstract: Pulmonary ventilation and gas exchange were determined during prolonged skiing (∼76% of ; cardiac output=26–27Lmin−1) using diagonal technique (DIA) for 40min followed by 10min of double poling (DPOL) and 10min of leg skiing (LEG). Exercise caused ∼2–5% reduction of arterial oxygen saturation . For a given cardiac output and , DPOL presented higher , lower and a more efficient pulmonary gas exchange, revealed by higher and and lower . The widened 2mmHgL−1 of cardiac output increase. However, for a given cardiac output and , exercise mode had an important influence on pulmonary ventilation and gas exchange. Highly trained cross-country skiers’ present about 2units reduction in from resting values during submaximal exercise at 76% of . Half of the reduction in saturation is accounted for by the rightward-shift of the oxygen dissociation curve of the haemoglobin. The exercise duration has almost no repercussion on pulmonary gas exchange in these athletes, with the small effect on associated to the increase in body core temperature. [Copyright &y& Elsevier]