For many fitness enthusiasts, it’s not a workout unless you break a sweat. But Japanese researchers have discovered sweating isn’t necessarily a good indicator of how hard someone is working. In fact, they found that men tend to sweat more easily than women and will begin to sweat sooner than women working out just as hard.

The researchers had men and women cycle for an hour in a controlled climate with increasing intervals of intensity. They used specialized capsules to measure the sweat rates on the forehead, chest, back, forearm and thigh, and compared sweat rates to changes in body temperature. They found that women needed to achieve higher body temperatures before they began sweating than did men.

The study also found that fitness training tended to lower the body temperature at which sweating began. But the effects of training were greater in men than in women.

“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.

Sweating helps an athlete stay cooler, allowing him or her to work more efficiently and for longer durations. The researchers suggested that women’s propensity to sweat less may be because they have less body fluid in the first place.

— Markian Hawryluk, The Bulletin