5 Reasons Your Comfy Activewear Really Stinks

Sweat loves synthetics. Science says so. You can thank Belgian microbiologists and their “trained odor panel” for determining beyond a doubt that sweaty polyester clothes “create a significantly higher malodor as compared to cotton clothing.” Their 2014 study found that not only does sweat-infested polyester smell far worse than cotton — “more musty, more ammonia, more sweaty and more sour,” in the panel’s words — polyester’s fibers are the perfect home for the malodorous Micrococcus bacteria, which flourish on synthetic textiles. The clothes in the study were bagged for 28 hours after a workout session to test for bacterial growth, so one big lesson here is: Wash your clothes as soon as possible after sweating in them.

Unfortunately, they can smell even after washing. It’s called “rebloom,” according to Procter & Gamble Co., maker of Tide detergent, which has researched the problem that affects 49 percent of Americans, the Wall Street Journal reported. Odor molecules from sweat and grime that remain in clothes after washing can re-stinkify fibers when they’re worn again. Complaints about persistent odors equal complaints about stains as the most common laundry problems, according to the company. P&G’s solution is a new “Odor Defense” line of Tide and Downy products. There are also several “sport” detergents on the market, which claim to be designed to remove those stinky odors.

It could be how you wash your clothes. Some experts say waiting too long to launder activewear clothes makes the problem worse. "How you store your workout clothes can also lead to additional odors — for example, leaving sweaty clothes in a closed up gym bag, locker, or hamper," Mary Zeitler, consumer scientist at the Whirlpool Corporation Institute of Home Science told Health.com. Others say Americans use too much detergent or laundry softener, which only coats the high-tech fibers, trapping the smelly stuff, or they cram too many clothes into one load so items don’t get sufficiently washed and rinsed.

You should try these laundry tips.  You don’t necessarily need a specialty detergent for cleaning your activewear.  Zeitler, as well as other laundry experts, suggest trying these natural solutions to getting your clothes odor-free. (I can also vouch, through trial and error with my own smelly exercise duds, that they work.)

• Wash your clothes as soon as possible after wearing. If you need to wait a day or two, let sweaty clothes air out so they’re not damp when you add them to the laundry hamper or bag.
• Turn your clothes inside out before washing so the inside, sweaty part is more easily cleaned.
• Don’t use more detergent than recommended and don’t cram too many clothes into one load.
• Add a cup of baking soda to the washer as it fills along with detergent. Baking soda is a natural deodorizer, but it works best in conjunction with detergent.
• Add a cup of vinegar to the rinse cycle to help get rid of soap build-up and odors. You can also try pre-soaking clothes in a vinegar-and-water solution before laundering.
• Give clothes the sniff test before drying. If they still have an odor, re-wash.