The Back on Track Men’s Long Johns may help to relieve groin, hip, and leg muscle discomfort through the use of Welltex technology. This technology uses your own body energy to create a soothing far infrared effect. The Long Johns come in two fabric options: cotton/polyester and polypropylene. Both fabrics are known for their great durability and effectiveness in wicking away sweat and humidity. Due to their excellent wicking qualities, this garment is well suited as an extra layer during physical activities.