Reigning Champ Core Sweatpants in Black. - size L (also in M) Reigning Champ Core Sweatpants in Black. - size L (also in M) 100% cotton. Elastic drawstring waist. Front slant pockets. Drawstring hem. REIG-MP1. RC-5018. Reigning Champ designs original fabrics then handcraft our garments for quality and strength. Everything is built with a purpose and inspired by the individuals around us. Reigning Champ is born on the coast, in Vancouver, Canada.