The Physiology of SWEAT!

I just finished my sister Vanessa’s workout and man am I sweating! It got me thinking about sweat and why it happens. Little do we realize, we are actually sweating all day, not just during exercise; sometimes we notice it in more areas than others. Sweating is a way to cool our bodies down and it is also produced when we are stressed or anxious (think sweaty palms).           

So let’s talk about what sweat is. Sweat is primarily composed of water along with tiny amounts of salt and other chemicals (protein, urea, and ammonia to get technical). There are different types of sweat glands in our bodies. Eccrine glands are the ones responsible for the sweat on my tank after my sister’s class. Apocrine glands are the ones located under our armpits (and in other areas such as the groin and breasts). When apocrine glands come into contact with bacteria, we get the BO smell.

Maintaining our body’s core temperature (approximately 37 degrees) is a delicate balance between heat production and heat loss. Our internal thermostat, located in a region of the brain known as the hypothalamus, is responsible for maintaining this balance. During exercise, heat production increases and our body responds via our blood, which distributes heat to our skin. Our nervous system also detects increases in our body temperature and communicates this info to our sweat glands. As the sweat is evaporated from our skin, our skin temperature lowers.

Why do some of us sweat more than others? This depends on your genetics, body mass, and how familiar your body is with exercising in hot and humid environments. So there is nothing gross about sweat, it’s natural and keeps you safe during exercise, so get sweating! Remember to replenish your loss of fluids with water (remember sweat is primarily water) because too much sweating can be dangerous. 

- Andi

Registered Physiotherapist and Kinesiologist