By Andrea Cheng
Updated Aug 27, 2016 @ 7:30 am
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Among the unsexy situations that plague us (yellow armpit stains, for one), anything that has to do with funky odors is definitely up there. And since we're in the business of giving you solid advice, we're going to address the "smelly" issue—instead of glossing over it, or being all squeamish, or avoiding this fact of life altogether. This brings us to the matter at hand: Workout clothes that still reek even after they've been washed. You know, it's that faint whiff of something off, even after several loads of laundry. You swear it's clean, so why is there a lingering B.O. scent? To get to the bottom of this chronic odor problem, a little bit of science needs to be involved (this won't be painful, promise!).

"Our fabrics are in contact with our skin 24/7, so that means all of our body soils—oil, skin cells, and salt—are transferred to our clothes," explains Mary Johnson, Tide + Downy's principal scientist. "At rest, our bodies produce one liter of sweat; 40 grams of sebum, or oil; 10 grams of skin cells (roughly two billion, which is akin to a handful of cornflakes); and 10 grams of salt. And if they're not removed properly from our clothes, they cause odor."

Icky, right? When we're working out, all of those numbers double or triple in amount. Factor in synthetic fabrics from sweat-wicking performance wear, and the situation worsens, because the material is constructed with invisible channels that funnel moisture from your body, through the fibers, and into the air, allowing you to stay dry during your sweat sesh. That means those clingy body soils are deeply embedded-slash-baked into the material in a way that it becomes a lost cause when you're using bargain laundry detergent. Two things can happen as a result: 1) You'll find yourself with a "permastink" situation, where you can smell the odor immediately after you launder the garment, or 2) A "rebloom" effect—it smells clean, but after exposure to heat and humidity, the odor re-emerges as the scent from your detergent fades. In both scenarios, the source of the problem lies with not having an effective detergent, which we'll go into later. there are a few things you can do to minimize the stench.

Wash Your Workout Clothes Right Away

Letting it sit overnight or, let's be real, a week, will only exacerbate the situation, because it breeds bacteria. "Bacteria eats body soils that are left on your clothes; body soils are food for bacteria," Johnson says. "The body soils smell, but then bacteria creates an additional smell."

Always Air-Dry

If you can't wash right away, at least let them air-dry. "Never put your clothes into a laundry hamper while they're still damp," Johnson says. "Odors will explore in dark, damp situations. Rather, let them air-dry before putting them in your hamper."

Flip Them Inside Out

The inner side of your clothing, obviously, has the most contact with your skin, which means it's best practice to always flip your clothes, but especially workout wear, for the most effective method to eliminate body soils.

Skip Your Fabric Softener

What good is a baby-soft top or a pair of leggings when they reek? Fabric softeners leave a coating on synthetic materials, preventing them from a good deep-clean and trapping all those odor-making culprits underneath.

Wash with Warm Water—Not Hot

Much like washing greasy dishes, the best way to eliminate oil is with hot water. Unfortunately, you shouldn't use hot water to launder your workout wear, because "it will damage the fibers in the fabrics, especially ones containing elastane," Johnson warns. "Instead, wash on a warm or cold settings." Always air-dry your workout wear after your launder them, too, for the same reason.

Pre-Treat Your Garment

Gwen Whiting and Lindsey Boyd of The Laundress, aka cleaning gurus, recommend soaking your activewear in a tepid water bath with a 1/4 cup of vinegar for 30 minutes prior to throwing it in the washer. Vinegar is a natural disinfectant (it contains five percent acetic acid), and it's often used as a substitute to bleach (never use bleach on workout wear).

Swap Performance Fabrics for Cotton

If your workout is less intensive (yoga, barre, etc) and doesn't warrant sweat-wicking fabrics, then trade in your synthetics for breathable natural fibers, like cotton, that aren't hydrophobic and don't attract dirt or odor.

Reach for Sport-Specific Detergents

Can't give up your performance pieces? And you don't want to ruin them with warm water? Use detergents that are formulated to clean sportswear, like Nathan Sport-Wash Performance Detergent ($13;, or ones that are designed to eliminate odor, like Tide's Odor Defense pods ($5; and Tide's Odor Rescue laundry booster packs ($5;, which contain oxygenated bleach that's safe for all fabrics and colors (and lets you wash your clothing in cold water!). If you're already out and odor has rebloomed, spritz The Laundress Sport Spray ($10;, an antibacterial, non-toxic solution to temporarily relieve any funky smells.