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

(1) This study describes the performance and the acute physiological respon ses of heat acclimatised cyclists during three sets of 5 x 20 s sprints fol lowed by a final sprint to exhaustion in temperate (mean +/- standard devia tion 20.2 +/-0.4 degreesC; 46 +/-2% humidity, 108.5 +/-1.4 kPa water vapour pressure) and in warm conditions (30.5 +/-0.4 degreesC; 47 +/- 10% humidit y, 206.8 +/-6.4 kPa water vapour pressure). (2) Oxygen consumption was grea ter in the warm condition and there was no evidence of an increased relianc e on anaerobic metabolism as has been reported for submaximal exercise in t he heat. (3) Subjects lost 2.1 +/-0.2% of body mass in 53.8 +/-0.2 min duri ng the warm condition. While the duration of the time to exhaustion final s print was 50 +/- 13 s during the warm condition it was 60 +/-7 s for the te mperate condition (p = 0.020). (C) 2001 Elsevier Science Ltd. All rights re served.