Author(s): Fernando M. Reis
The aim of this study was to compare the local and global sweat rates between the follicular and luteal phases of ovulatory cycles during a progressive exercise until exhaustion, held in a warm and dry environment. Eight women found to be healthy after undergoing a physical examination and with regular, ovulatory menstrual cycles participated in this study. The exercise was performed on a cycle ergometer according to the American College of Sports Medicine protocol. The test began with a power of 50 watts in increments of 25 watts every 2 minutes until exhaustion, while maintaining a speed of 50 rpm. The local sweating rate was measured using filter paper and the global sweating rate was estimated using body weight. Ovulation was detected both by serial transvaginal ultrasonography and serum progesterone measurement. Rectal temperature was higher in the luteal phase (37.54 ± 0.03ºC) when compared with the follicular phase (37.28 ± 0.05ºC, p<0.05) and increased significantly following exercise at both phases of menstrual cycle. The local and global sweat rates during exercise did not differ between the follicular phase (local 0.368 ± 0.111; global 3.03 ± 0.17 g.m-2.min-1) and the luteal phase (local 0.240 ± 0.063; global 3.20 ± 0.39 g.m-2.min-1) of menstrual cycle. Also in the recovery period after exercise, there were no differences in the sweat rate according to menstrual cycle phase (p>0.05). In conclusion, under the environmental conditions tested in this study, the local and global sweat rates elicited by progressive exercise to exhaustion were not influenced by the phases of the menstrual cycle.
