Clothing materials help mask or maximize bacterial body odors
My kids are young enough to find the idea of a sweaty, stinky adult as being funny, in a sort of yucky way. While they do manage to get themselves plenty dirty when running around outside, they aren’t producing the proteins from their apocrine glands that bacteria love to eat, so they can only get so smelly. If they really wanted to work on grossing out their friends before hitting puberty, it turns out there are easy ways to encourage bacterial growth that even a child can handle. To boost your body odor, it turns out all you have to do is wear more polyester when working out.
To see why polyester makes a difference in one’s smell, it’s good to start with why we smell in the first place. As noted above, even kids can get sweaty to cool off when their body temperature rises, but most sweat is just water, and thus doesn’t give you that ripe odor most adults associate with vigorous exertion. To really stink, you need a good amount of both Staphylococci and Corynebacteria bacteria, which feed on the proteins found in the sweat of your armpits and groin. If you had to choose, Corynebacteria carries the stronger smell, but the best way to cultivate that strain of bacteria may be to be male, so there’s probably not a lot to be done on that front. Instead, to make the most of the bacteria you have, your best bet is to get rid of breathable cottons for a nice, shiny polyester jersey when exercising.
The pungence of polyester
Lots of sporty clothing is made from polyester thanks to its low cost and high durability. They also don’t shrink in the dryer because they don’t really absorb much moisture in the first place, although many are good at grabbing hold of the oils produced by our skin. This combination means that, unlike a cotton shirt which will absorb some bacteria-laden sweat before it can get to our noses, polyester shirts will allow odors to propagate, plus carry oily snacks for bacteria to much on, even after you’ve finished sweating.
Beyond enabling your Corynebacteria to be all they can be, polyester may also bring a third strain of bacteria to your workouts! A genus called Micrococcus has been found to grow quite happily on synthetic fibers like polyester but not only skin or cotton, so you’ll miss out on it entirely if wearing a standard t-shirt. These bacteria do turn up other places, but if your armpits are smelly enough on their own, this is probably the fastest way to make things better. Or worse? It’s hard to know with second graders.
My second grader asked: Why do men have more Corynebacteria in their armpits? I think mommy’s pretty stinky sometimes too.
As far as I can tell, this might be tied to men generally having slightly more acidic skin than women. This is thought to lower the amount of bacterial diversity on the skin, which basically frees up territory and resources for whatever species is left. In this case, that’d be Corynebacteria, which can then grow with less competition on the skin.
Source: Why does my exercise clothing smell?, BBC Fitness