If every workout leaves you itching, your clothing could be to blame. Cheap, synthetic materials like polyester and nylon, used in everything from shirts to underwear, sometimes cause people with sensitive skin to feel like they're coming down with the chicken pox. Check clothing labels before you purchase; Lycra (spandex) is less likely to irritate, according to the ACAAI. Better yet, look for natural fibers, including high-quality, naturally wicking wool.
Be sure to avoid workout clothing, socks, and underwear marketed as "odor-fighting," "odor-free," "antimicrobial," or "Microban." These things could contain compounds that many public health experts say we should avoid.