Exercise responses after short- and long-term residence at 2,200 meters

Submaximal and maximal exercise responses were examined in persons (age, 19-30 years) residing at a moderate altitude for different periods of time. Long-term residents (LTR; 44 males, 11 females) had lived continuously between 1,830 and 2,200 m for 2 years or longer before testing. Short-term residents (STR; 22 males, 30 females), previously lowlanders, arrived at 2,200 m within 10 to 21 days before testing. Incremented tests on a motor-driven treadmill were performed until voluntary exhaustion. Cardiorespiratory measures and ratings of perceived exertion (RPE) were examined at 60% and 100% of maximal oxygen uptake (VO2max). With the exception of minute ventilation (VE), which was higher (p less than 0.05) in STR females, maximal responses were comparable in STR and LTR females. All maximal responses were similar in STR and LTR males. Both VE and RPE at 60% VO2max were significantly higher in STR males and females than in their LTR counterparts. Plasma lipid responses to the maximal exercise may indicate a greater contribution of the triglyceride pool of adipose tissue to fatty acid mobilization during exercise in the LTR compared to STR male subjects.