Prevent exercise-triggered skin problems before they start. By Emma Haak Before the Gym Step 1: Throw this in your bag. Chances are your gym isn't washing its towels in the gentle, fragrance-free laundry soap you use at home. So if you have sensitive skin, put a towel from home in your gym bag. Residue from commercial detergents (like those gyms often use) on towels can lead to irritation and even contact dermatitis, says Lisa Airan, MD, a board-certified dermatologist in New York.