Objective: We examined the sweat rate (SR), sweat volume (SV), sweat sodium concentration (S[Na+]) and changes in thirst perception (TP), in premenopausal (preM), perimenopausal (periM) and postmenopausal (postM) women after moderate exercise.
Methods: Thirty healthy women comprising preM (22.5 ± 0.8 yrs, n = 10), periM (46.5 ± 1.1 yrs, n = 10) and postM (52.2 ± 0.9 yrs, n = 10) participated in the study. All participants gave informed consent. TP was rated using the visual analogue scale. Sweat was obtained with sweat suction apparatus from a 120 cm2 circular area marked on the skin of the face and neck, after moderate exercise, i.e. a 15 min walk on the treadmill at a speed of 4.2 km/h at 27°C. The start time was noted, SR, SV and S[Na+] were determined.
Results: Exercise induced a significant change in TP in all groups, of which the postM women exhibited the lowest thirst ratings. Although there was no significant difference in SV and S[Na+] between the groups, the periM women showed a significantly higher SR compared to both preM and postM groups. A significant and positive correlation existed between TP, SR, SV and S[Na+] values.
Conclusion: These data indicate that an increase in sweat rate and volume produces a concomitant increase in thirst perception in women during moderate exercise, but sodium loss is reduced.
Key words: Exercise; Menopause; Sweating; Thirst perception