Why do we Sweat?

You’re sitting at the table enjoying a delicious meal and unknowingly you bite into a chili pepper. Without moving any limbs still sitting, with your mouth on fire, you break out in a sweat. You wipe off the sweat thinking that the air conditioner must have broken down. The next day you decide to take your dog for a leisurely walk and at the end of the hour, after stopping to chat with some friends you met along the way, you find yourself soaked in sweat thus feeling satisfied with your intense physical effort. Although most people gauge the intensity of their workouts by how much they sweat, sweating in reality is the body’s mechanism to cool itself down and regulate its internal temperature. We might not notice it, but sweating is an activity which is performed by our bodies all day long, even in cold weather. Being in hot weather, exercising, eating spicy/hot food and being nervous all increase our internal body temperature, which in turn causes us to sweat, thus, allowing the body to cool down. Excess heat is removed from the body when sweat evaporates from the skin. You must have noticed that during hot humid days you are more uncomfortable than on a hot dry day. This is because sweat does not evaporate easily in humid weather, as the air already has enough water vapor in it. As a result sweat remains on the skin and the body does not cool down efficiently unlike during hot dry days when sweat quickly evaporates form the skin. In both situations, drinking enough fluids is a must as dehydration can occur very quickly.

There are over 2 million sweat glands in the skin divided into two types- the eccrine and apocrine glands. The eccrine glands which are the most numerous type, are found all over the body mainly on the soles of feet, palms and the forehead. Apocrine glands which typically end in hair follicles and become active during puberty are confined to the armpits, genitals and scalp. Sweat from eccrine glands produce sodium, chloride, potassium and is salty and clear while sweat from the apocrine glands contain proteins and fatty acids thus giving it a thicker or yellowish color. Sweat itself has no odor, only when it comes in contact with bacteria and hair on skin, will it develop an odor thus requiring the use of deodorants.

While participating actively in an aerobics class will most likely cause you to sweat, the thought of your mother-in-law staying with you for three weeks might also make your palms damp and challenge your deodorant. Anxiety and nervousness trigger an increase in sympathetic nerve activity along with an increase in epinephrine secretion form the adrenal gland which acts on sweat glands mainly on the palms and armpits producing sweat. Other situations like making a speech, giving a presentation, or interviewing for a job also create a similar ‘fight or flight’ response, with an increase in heart rate as the body perceives imminent danger. Sweat glands are then activated as the body prepares to cool itself down.

Some people believe that the amount of sweat and how quickly you sweat is an indicator of your fitness level. For example, if you climb up a flight of stairs really fast and break out in a sweat you might be considered unfit by some. Yet others believe that the more you sweat and the quicker you sweat is an indication of physical fitness. While a fitter person generally does sweat more quickly, there are still several factors that can affect individual sweating, including genes, medical conditions involving the thyroid, medications, menopause, and obesity. Even the climate your body is acclimated to and the temperature in which you are exercising in, can affect how much you sweat. So, sweating by itself is also not a good indicator of how hard you are exercising as one person may work out at a moderate intensity and sweat profusely, while someone else might work out at a higher intensity and barely break a sweat. Remember to gauge your workouts not by how much you sweat but by calories burned and the intensity.

Although considered embarrassing by some, sweating is a normal and vital bodily function, without which our bodies would overheat. Excessive sweating, or not sweating at all however, could indicate an underlying medical problem. If you suspect abnormal sweating, don’t break out in a sweat over it, instead talk to your doctor and understand your treatment options.

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