Acute responses of heat acclimatised cyclists to intermittent sprints in temperate and warm conditions

Abstract (1) This study describes the performance and the acute physiological responses of heat acclimatised cyclists during three sets of 5×20 s sprints followed by a final sprint to exhaustion in temperate (mean±standard deviation 20.2±0.4°C; 46±2% humidity, 108.5±1.4 kPa water vapour pressure) and in warm conditions (30.5±0.4°C; 47±10% humidity, 206.8±6.4 kPa water vapour pressure). (2) Oxygen consumption was greater in the warm condition and there was no evidence of an increased reliance on anaerobic metabolism as has been reported for submaximal exercise in the heat. (3) Subjects lost 2.1±0.2% of body mass in 53.8±0.2 min during the warm condition. While the duration of the time to exhaustion final sprint was 50±13 s during the warm condition it was 60±7 s for the temperate condition ( p =0.020).