No Sweat?

Ever wonder why the person working out next to you is sweating so much that they are creating their own micro-climate equivalent to that of a rain forest while you are simply "glistening", and yet you are sure you are putting out just as much effort?

There are a number of factors that determine how much we sweat.  Perhaps the most significant determining factor in our sweat rates is gender.  While it may not be true that women merely perspire or mist while men sweat, it is true that men sweat more than women.  The reason for this has not been researched very thoroughly.  There is a new study, however, that compared a group of trained athletes, male and female, as well as an age- and gender-matched group of untrained volunteers.  The participants were monitored while they rode stationary bikes in a physiology lab heated to 86 degrees.  The researchers discovered that the fit men perspired the most, and significantly more than the fit women.  They also determined that the men were not sweating more because they were using more sweat glands, but instead the women were simply producing less sweat from each gland.  One theory that has not yet been proven is that men's higher sweat rates are due to higher levels of testosterone.  Earlier studies that show that the sweat rates of prepubertal boys and girls are roughly the same suggest that this theory may be valid.

Another factor that determines an individual's sweat rate is their level of fitness.  Physical activity generates body heat, and as the intensity and duration of the activity increases, so does our body's core temperature.  Without an internal or external process to cool our bodies our core temperature will continue to rise.  Once it reaches a critical level of about 104 degrees, our body begins to shut down and we are in a life threatening situation.   Sweat functions to cool our bodies.  As a person becomes more physically fit their body becomes more efficient at cooling and begins to sweat at a lower core temperature.  The study mentioned above validates this as it found that the unfit women, by a wide margin, perspired the least.  Their core temperatures rose significantly before they began to sweat at full capacity. 

Finally, we are all individuals, and just as is the case with our other physical attributes, we are all unique.  So the person who is standing in a wading pool at the end of their workout didn't necessarily work any harder than the person who is simply glistening.  Remember, though, generating heat during your workouts means you are kicking in that metabolic burn.