Hydration Series - Why Do We Sweat?

Weird question, right? Well, it’s important for our Powell Performance Hydration Series to start at the beginning.


So, to answer this great question, the biggest reason is that we are endotherms (we control our own temperature) because we are hot blooded.


Comparatively, cold blooded animals (reptiles for example) use external heat in order to stay at their necessary core temperature. This is why you’ll often see them out “sun bathing” during the day.


We produce heat through our metabolic reactions and activities. When we get hot through these metabolic reactions, we have to get rid of our heat by putting it out into the environment, this is where sweating comes in handy. Through the sweat leaving our system we are able to have it evaporate on our skin and cool us, while simultaneously expelling our heat outwards into the environment around us.


On a positive note we are THE BEST SWEATERS IN THE WORLD! No, seriously, of the animal kingdom, we sweat the most by A LOT. Interestingly, very few animals sweat period, camels and horse come join us in the sweat lodge!


Why are we so good at sweating?


Why do we sweat the most? Most likely it helped our ancestors as hunters trying to chase down prey on the Serengeti where we could maintain longer periods of running without having to stop to cool down. The ability to move for longer periods of time at moderate to high speeds of 15-20MPH was useful because there was no way they would catch these prey animals (gazelles, antelope, Koodoo, and other mammals) at their top speeds of 30-40MPH.


The competitive advantage at that point was that those same animals have to stop and pant, much like your pet dog does, to bring down their temperature. This allows us to run them down long term, get them tired and almost to exhaustion, then be able to make the kill and eat them.



How does it work?

Depending on a person’s size they can have from 1.5 and 5 million sweat glands! All those crazy days of ringing out your T-shirt after a big workout or practices makes sense now right…? 

Those sweat glands are usually one of two types: eccrine and apocrine

Eccrine glands are what produce most sweat you see while training. Found mostly in the palm, soles and face, they are small, highly numbered and are found, at least in small numbers EVERYWHERE on the body. Interesting fact, there can be upwards of 700 glands per square centimeter of skin! While in the less concentrated spots as few as 20 per square centimeter.

These glands drive the most important part of sweating… to cool us down. Thus for this article’s intentions, we’ll spend more time discussing them. It’s also important to note that how both the apocrine and eccrine glands are stimulated is similar, HOW they are stimulated is very different, we’ll go into details later in the article.

Apocrine glands, conversely, produces a different sweat that comes from the base of hair follicles and moves up it to the skin’s surface.  These glands are much more concentrated and only found in a few spots, specifically your arm pits and groin. The secretion they produce is thicker.


Anytime we talk about sweat, it’s hard to not also imagine a specific scent with it. Thankfully, the actual secretion of sweat does not have any smell. Instead, it is the reaction of the bacteria found on human skin to break down that secretion (yummy…) that causes the smell. Specifically, the apocrine gland secretions lead to the odor that comes with sweating. 

Sorry gents… Males typically have more apocrine glands, due not only to their usually bigger size but also a higher concentration of them in the armpits and groin. Puberty anyone? 


What gets these glands going?

We know what the 2 major kinds of sweat glands do and where they are located, but what makes them start working?

Heat… duh?

Right! Specifically heat increased at the inner core of our body that raises our entire body temperature.

This is recognized and detected by neurons in the hypothalamus that are sensitive to heat. Once it detects the change in temperature, it works with the reset of that section to release a neurotransmitter, acetylcholine, on a local level near with neurons near the sweat glands.

Once the secretion starts and the hypothalamus is used to create this “cascade” of hormones, neurotransmitters, etc. it leads to sweat being secreted. Sweat that starts due to theis trigger is known as “hypothalamic” sweating.

Ok, so why are my palms sweaty on a first date?!

We’ve all been there… you’re on a date, in an interview or are about to present in front of a group, suddenly you feel hot, clammy and sweaty. What the hell! This isn’t temperature related!

Sweating can also be due to emotional stress. 

This version of sweating is called, “cortical” sweating. It Is thought to be an evolutionary mechanism. The idea is that those same ancestors who chased the mammals around the Serengeti, used this reaction to maintain their grip in high stress situations. Hopefully, in another few hundred or thousand years we can get rid of this one too…

More spice / heat please!

Watching people on the food network take on spicy eating challenges got you sweating? Unable to even level up to the medium level of spice or heat? Well than you know all about this last type of sweating, called “medullary”

Spicy food contains compounds that will often bind to sensors in the mouth and lead to sweat pouring from the face.

Wrap up

Remember that we are the world champs at sweating for good reasons, it is definitely a major component for why our species is still here. When we look at our furry friends like horses, camels and even man’s best friend, the dog, we aren’t too different, just better prepared.

Due to those animals being covered in hair they can only use some of their apocrine glands and we’ll find some eccrine glands down in paws of some, but they still rely on things like panting to regulate their body temperature to an appropriate level.

So, the question now is, how much do I need to drink to crush my training, goals, competitions, etc?


What supplements should I use?

Should I salt my food?


We’ll get deeper into these questions and more as we go through our Powell Performance Hydration Series to answer all those questions and more.


If you have more more questions or want a want to learn more from our Powell Performance Staff, please CLICK HERE for a free consultation!

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