Women Don't Sweat as Much or as Effectively As Men

Researchers measured the rate at which both men and women perspired while biking for an hour under controlled conditions. Men who were physically fit sweat more readily than anyone else, and men, in general, also appeared to benefit more from physical training than did women. This difference became more pronounced as the activity level increased.
Physically fit people begin to sweat at a lower core body temperature. And since sweating is our body's way of cooling off (and keeping from overheating), this allowed men to perform longer, according to the researchers. Inactive women had the lowest sweat rate.
"It appears that women are at a disadvantage when they need to sweat a lot during exercise, especially in hot conditions," said Yoshimitsu Inoue, the study's coordinator and a researcher at Osaka International University in Japan.
The researchers had 37 subjects cycle for an hour at increasing intensities - active subjects had participated in endurance sports for more than six years, while inactive subjects had, for the most part, not performed regular physical activity in the previous three years. The scientists measured the subjects' temperature, sweat rate and activated sweat glands for a number of sites on the body, including the forehead and thigh. The information was used to calculate sweat gland output and measure performance.
Fit women had higher sweat rates than inactive men, though this difference was not statistically significant. But fit men saw a more dramatic improvement in their performance over inactive men than did fit women over inactive women. Overall, fit men sweat the most.
Sweat output per gland was significantly higher for fit subjects during more intense exercise than for their unfit counterparts, but fit men's sweat gland output increased more rapidly than the others as their body temperature rose.
Untrained women didn't fully activated their sweat glands until they reached a more intense level of exercise than the others, whose sweat glands activated sooner.
Prior research has shown a link between the male sex-hormone testosterone, physical training and an increase in sweat rate. Although they did not measure the hormone among their subjects, the researchers suggest the hormone may play a role in their results.
/LiveScience.com Wynne Parry