There’s that day when the workout clothes show up in the laundry–actually, hopefully it is every day, right? My Favorite Guy works out hard at the gym playing racquetball with his buddies–and has the great physique to prove it! And you can smell…I mean, TELL…he’s done a great workout when he brings home those soaking wet clothes.
If we aren’t careful with the laundry, though, you can STILL tell he’s had a good workout even after the clothes are washed, dried, and…well, no way are they being put away stinky.
With workout clothes, the offending smell is often focused in the armpit area, but you can use this technique anywhere on them.
It’s easy-peasy, really. Just keep a spray bottle of full strength vinegar (white or cider both work fine) in the laundry room. 
Once you’ve changed out of those sweaty, gold-medal worthy workout clothes, thoroughly spray the armpit area and any other areas that tend to keep lingering smells with the vinegar. Toss it in the washer and wash clothes as you normally would or, if a little extra help is needed, use the tips from the Stinky Laundry post.
One quick note: Avoid tossing sweaty workout clothes in the regular clothes hamper, just as you’d avoid tossing wet towels or washcloths in. The dampness will cause all the clothes to start to mildew and smell. You can hang the sweaty, wet stuff over the side of the hamper or lay it out on the washing machine to wait its reincarnation as fresh, workout ready threads.