Efficient packers may only bring two or three sets of workout clothes on vacation—even if they’ll be gone a week or more. But without a plan, taking them for a second spin can lead to serious odor and even increase your risk of infection, says Rachael McQueen, Ph.D., an associate professor and textile science researcher at the University of Alberta in Canada.
Bacteria can survive on clothes for weeks, but since it all originated from your skin, coming back in contact with it won’t cause rashes or athlete’s foot (which you might get from other people’s bacteria), McQueen says. Still, damp fabrics can cause microtears in the skin and in women, lead to UTIs.
The buildup of bacteria can also leave behind a stench. To minimize it, only make this a habit with cotton or wool performance apparel, which don’t hold onto odor as much as polyester pieces do.
If you know you’ll have to re-wear an outfit, wash everything in the tub, shower, or sink immediately post-workout. McQueen suggests using travel detergent or even hotel shampoo rather than hand soap, which is more abrasive and will wear down the fabric. Hang the items in a well-ventilated space such as near a balcony or air vent.
The bottom line:
At the very least, make sure dirty workout clothes are completely dry before re-wearing them, McQueen says.