Gender differences in sweat lactate

Abstract

Sweat rate may affect sweat lactate concentration. The current study examined potential gender differences in sweat lactate concentrations because of varying sweat rates. Males (n = 6) and females (n = 6) of similar age, percentage body fat, and maximal oxygen consumption (VO2max) completed constant load (CON) cycling (30 min--approximately 40% VO2max) and interval cycling (INT) (15 1-min intervals each separated by 1 min of rest) trials at 32 (1) degrees C wet bulb globe temperature (WBGT). Trials were preceded by 15 min of warm-up (0.5 kp, 60 rpms) and followed by 15 min of rest. Blood and sweat samples were collected at 15, 25, 35, 45, and 60 min during each trial. Total body water loss was used to calculate sweat rate. Blood lactate concentrations (CON approximately equal to 2 mmol.l-1, INT approximately equal to 6 mmol.l-1) and sweat lactate concentrations (CON and INT approximately equal to 12 mmol.l-1) were not significantly different (P > 0.05) at any time between genders for CON or INT. Overall sweat rates (ml.h-1) were not significantly different (P > 0.05) between trials but were significantly greater (P < or = 0.05) for males than for females for CON [779.7 (292.6) versus 450.3 (84.6) ml.h-1] and INT [798.0 (268.3) versus 503.0 (41.4) ml.h-1]. However, correcting for surface area diminished the difference [CON: 390.7 (134.4) versus 277.7 (44.4) ml.h-1, INT: 401.5 (124.1) versus 310.6 (23.4) ml.h-1 (P < or = 0.07)]. Estimated total lactate secretion was significantly greater (P < or = 0.05) in males for CON and INT. Results suggest that sweat rate differences do not affect sweat lactate concentrations between genders.

Sweat lactate response between males with high and low aerobic fitness

“…Consistent with other studies (Ament et al 1997;Green et al 2000aGreen et al , 2000bGreen et al , 2001, the sweat lactate concentration in the current study was initially high and reached a plateau within 30 min (Fig. 4) regardless of fitness.…”

“…After each sample was collected the Opsite device was removed, the skin of the lower back was dried with a clean cotton towel and a new sweat collection device was positioned in the same location. This method has been utilized in previous studies (Green et al 2000a(Green et al , 2000b(Green et al , 2001 to eliminate contamination of serial samples. Also, because the parafilm is impermeable, sweat samples are altered minimally by evaporation.…”

“…Although less specific than actual ATP measures, this constituent provides an indirect method for assessing variations in the metabolic tendencies of sweat glands. For example, in a study by Green et al (2000b) sweat rates (SR) were significantly greater in males, with no significant differences between males and females for sweat lactate concentrations. Because females possess a greater number of heat-activated sweat glands (Bar-Or et al 1968) it was concluded that there may be potentially different metabolic tendencies between eccrine glands in males and females (Green et al 2000b).…”

“…For example, in a study by Green et al (2000b) sweat rates (SR) were significantly greater in males, with no significant differences between males and females for sweat lactate concentrations. Because females possess a greater number of heat-activated sweat glands (Bar-Or et al 1968) it was concluded that there may be potentially different metabolic tendencies between eccrine glands in males and females (Green et al 2000b). Based on similar SR and sweat lactate concentrations, it was also speculated that younger and middle-aged males with similar relative peak oxygen consumption ( _ V O 2 peak) values demonstrate similar metabolic tendencies in eccrine glands (Green et al 2001).…”

Gender-Related Differences in the Physiology of the Stratum Corneum

“…Other physiological differences in the skin of men and women have also been described: gender-related differences in lipid composition [6], sphingolipids [3], skin bacteria [7] and the overall sweat rates [17] have been reported. With increasing age, the skin of women becomes thinner than the skin of men [2].…”