Gym stink is a hazard of regularly sweating; however, there are a few tricks to get odor out of your gym clothes. First, let them air as soon as you can before throwing them in the hamper to prevent them from staying moist and musty. Next, presoak them in a mix of white vinegar and water, or add a cup of baking soda to your wash. If that's still not enough, you can try stripping them by soaking them in a combination of borax, laundry soda, laundry powder, and hot water for a few hours before washing.