Why expensive synthetic workout gear stinks

Perhaps we should have worn cotton?
Perhaps we should have worn cotton?
Image: Reuters/Marcos Brindicci
We may earn a commission from links on this page.

In workout wear (and even with denim pants), synthetic materials like polyester and elastane are crucial elements to help designers bring together comfort, fit and fashion. Newer fabrics are also longer-lasting, easy to clean, and don’t wrinkle easily. And polyester can wick sweat away from your skin, keeping you feeling moisture-free during intensive workouts.

But as anyone who has invested in expensive new-fangled workout gear can attest, synthetic fabrics can smell a lot worse after exercising than cotton clothing. A new study by researchers at the University of Ghent confirms that observation.

Researchers had (pdf, sign-in required) 26 healthy people (13 men and 13 women) wear 100% polyester t-shirts while doing an intensive bicycle spinning class for an hour. They then collected and incubated the shirts for 28 hours to let the bacteria on the shirts grow and, then had a trained odor panel assess their smell. They also did this with 100% cotton shirts and mixed-material shirts, for comparison.

The panelists concluded that, compared to cotton shirts, polyester clothing smelled “significantly less pleasant, and additionally, more intense, more musty, more ammonia, more strong, more sweaty and more sour.”

From a bacterial analysis standpoint, DNA extracted from the t-shirt samples—and participants’ armpit areas—showed that microcci, which typically causes malodor, were predominantly found on synthetic fabrics. Some were also found on mixed synthetic textile clothes (such as part-cotton, part-elastane clothing) as well. But microcci wasn’t able to grow on cotton textiles.

So if dousing yourself in underarm deodorant while you work out in style isn’t cutting it, try switching to plain old cotton.