Ah, summertime — the time of year for barbecues, lemonade and changing my T-shirt four freaking times a day because I keep sweating through them like a disgusting beast. I can’t help it, I’m a sweaty dude, but recently I got to thinking: Body hair keeps people warm, right? So if I shave my pits, does that mean that I’ll sweat less?
According to dermatologist Anthony Rossi, the answer isn’t so simple. “Under arm hair doesn’t affect sweat per se. Sweat comes from glands inside, so it’s regulated by your internal temperature,” Rossi explains. Now, the body hair can indirectly make you a little bit warmer, thus causing more sweating, but the amount of hair you have doesn’t affect how much your body sweats.
That said, while underarm hair can’t affect how much you sweat, it can make you more sweaty and there are several reasons for this. For one, when you sweat, the whole point of it is to cool down your body from that liquid and the evaporation of that liquid, but the sweat evaporates more quickly off your skin than it does your hair. Just think of it like when you exit a pool and let yourself air-dry — your hair is the last place to get dry. So, your underarm hair is holding onto that moisture longer than your skin would, and this is making it swampier. It’s also causing you to get more sweat onto your shirt.
That moisture in the area is also going to affect how much you smell, as the increase in moisture is going to attract and create more bacteria. The breakdown of that bacteria is what makes your underarms smell, as Rossi explains that sweat has no odor on its own — that familiar B.O. stink all comes from bacteria.
Underarm hair is also making you sweatier by blocking the effectiveness of antiperspirants. Now, I’m not talking about deodorants here, as Rossi explains that those are merely “a fragrance,” but as for antiperspirants, Rossi explains that, “antiperspirants work by creating little aluminum-chloride crystals that form salt plugs that go into the gland — that’s why they’re called antiperspirants, because they’re plugging the sweat gland.”
Rossi says that the way to make an antiperspirant more effective is to put it on before going to sleep, as those plugs take time to form. Underarm hair can affect antiperspirants because the hairier your pits are, the less of that antiperspirant is making it onto your skin, and they only work when they’re actually on your skin. In other words, those gross white chunks of antiperspirant tangled into your underarm hair aren’t making you sweat any less or smell any better.
Generally speaking, body hair on the rest of your body is going to make you sweatier as well, be it on your swampy butt, sweaty back or your perpetually smell balls. The reason for this is the same as it is for your pits: because the hair is collecting that moisture, it’s making you more moist, which then soaks into your clothing. Rossi explains that this is part of the reason why swimmers shave their bodies — not only does hair create drag, but it also collects moisture. Shaving everywhere else might not cause as profound of a change as your armpits, but it will decrease the moisture on your body and make you a little cooler (especially if you’re a really hairy dude).
At the very least though, trimming or outright shaving under your armpits will help you to be a little less sweaty, which should make for less pit stains and less wardrobe changes on hot summer days. Hell, you may even save a few T-shirts from those dreaded yellow-y stains.
Now, if you’ll excuse me, I’m going to shave my pits before I change my shirt again.