Aerobic power as a factor in women's response to work in hot environments.
Twelve young women, athletes (n = 6) and nonathletes (n = 6), walked on a treadmill at loads equivalent to approximately 30% Vo2 max for two 50-min periods in three environments: 1) 28 degrees C, 45% rh, 2) 35 degrees C, 65% rh, and 3) 48 degrees C, 10% rh. There were no differences between groups in rectal temperature, heart rate, evaporative heat loss, or mean skin temperature at 28 or 35 degrees C or during the first work period in the 48 degrees C environment. However, a significantly lower cardiac output (Q) and stroke volume (SV) observed for nonathletes by the 46th min of work at 48 degrees C may explain why no nonathletes were able to complete a 2nd h of work while four of six athletes successfully finished the period. It appears that in conditions of severe heat stress (48 degrees C) athletes were able to maintain a cardiac output sufficient to meet the metabolic requirements and the large increase in peripheral blood flow for a longer period of time than nonathletes.
D000064:Acclimatization; D000328:Adult; D001794:Blood Pressure; D001831:Body Temperature; D001833:Body Temperature Regulation; D002302:Cardiac Output; D004573:Electrolytes / Q000097:blood; D004777:Environment; D005260:Female; D005542:Forearm / Q000098:blood supply; D006339:Heart Rate; D006358:Hot Temperature; D006801:Humans; D010101:Oxygen Consumption; D005082:Physical Exertion; D010953:Plasma Volume; D012039:Regional Blood Flow; D012737:Sex Factors
D004573:Electrolytes