We investigated the influence of altering exercise intensity (150, 300, and 450 kpm/min) on the resetting of the core temperature threshold for the onset of the sweating rate (Ṁsw) and the alteration of sweating sensitivity during the menstrual cycle in women. Five women underwent cycling exercise for 30 min in both the luteal and follicular phases under controlled neutral environmental conditions (T: 25°C, RH: 55%). A significantly higher rectal temperature (Tre) was seen in the luteal phase at all exercise intensities, and the same time course of the Tre response with a constant difference of ∼0.2°C was shown between the follicular phase and the luteal phase. The Tre threshold for Ṁsw was also apparently shifted rightward a constant value of 0.2°C from the follicular phase to the luteal phase, independent of the alteration of exercise intensity. The slope of the Ṁsw-Tre relationship in the follicular phase did not differ from that in the luteal phase. These results indicate that (1) a rightward shift in the Tre threshold from the follicular phase to the luteal phase can be observed independent of any alteration of the exercise intensity
and (2) the sensitivity of Ṁsw is also not physiologically influenced by exercise intensity. Thus, alterative thermoregulation during the menstrual cycle was fundamentally unaffected by the change of exercise intensity. © 2002 Elsevier Science Inc. All rights reserved.