Sweating accompanies most exercise sessions, yet many people are confused about the meaning of sweat. Sweating is the body's primary method of keeping cool. Under normal conditions, sweating occurs in small unnoticeable amounts in response to day to day activities. As the energy demands of the body increase, there is an increase in metabolic activity which raises the core temperature of the body. Just like an overheated car that will not work properly, an overheated body will not be able to perform as required. The body has an incredible amount of control over sweating in response to activity and ambient temperature/humidity.  

An interesting progression occurs in an individual going from no activity in mild temperature to working or exercising in a hot environment. As the individual becomes dehydrated, they may experience muscles cramps and discomfort. Upon continued exposure to heat and activity without compensating with fluid intake, there may be changes to mental acuity, and the skin will become white or flush, and the person will be sweating profusely. Sweating is present in these two stages of heat illness because the body is trying desperately to cool itself. As the exposure continues and the fluid intake does not meet the demand, the body will shut down the sweat mechanism. The skin may become dry, hot, and red. At this point, the body is trying to conserve any available fluid to maintain normal function of the cells.

Many people are under the assumption that those who are unfit sweat more than those who are fit. The reverse is actually true. A fit individual sweats "more" because the body is better adapted for cooling itself so that the individual may continue to perform. Sweat typically begins earlier during exercise in a fit individual. Anecdotally, it seems that unfit people may sweat at lower intensities than fit people. A lower intensity may not elevate the body temperature of a fit individual enough to cause them to sweat. The same intensity may be so strenuous for an unfit person that they begin to sweat in order to cool their body. The fit individual tends to have less "salty" sweat than an unfit individual. The body learns that essential minerals (sodium, potassium, etc) are lost with sweating and without conservation of these minerals, an individual who sweats often will quickly create a mineral imbalance. Any individual with higher frequency of physical activity (athletes, construction workers), lose less salt than their inactive counterparts.

Sweat may be a good indicator of increased core temperature (possibly signifying the beginning stages of a warm up), but do not forget the effects that cold, heat, humidity, and elevation have on sweat rates. As a general rule for most activities, the body will begin to warm up after about 10 minutes of activity. Perhaps one of the greatest misconceptions is that sweat equals calories burned. Remember, sweat is a cooling mechanism and results in fluid loss, not the disappearance of fat! Sweating will result in a lower number on the scale, but as soon as fluids are replaced, the higher number will reappear. Those looking to lose weight should not waste time in saunas or steam rooms, but they should exercise longer or more frequently. Finally, avoid rubber suits or neoprene belly suits that promote sweating. More often than not, these devices make exercise uncomfortable due to the elevated body temperature. Instead of sweating more, exercise harder!

Manny Escalante, Jr. MA, ATC, CPT has a Master's Degree in Sports Medicine,

Certified Athletic Trainer, and Certified Personal Trainer.

Competed in bodybuilding and a 3 time Ironman Triathlon Finisher