Mariusz Kupczak was born with cerebral palsy, muscular atrophy, and right-sided hemiparesis. In his everyday life, he uses a wheelchair but despite that, he decided to become a professional bodybuilder. He is a multiple champion of Poland. In 2017, he won European Championship and World Championship. Following that, he decided to end his career. However, in 2019 he returned to training. He claims that bodybuilding helps him fight depression he has been struggling with for many years. In autumn 2019 he once again became the Champion of Poland, as well as the World Champion during an event hosted in Lithuania.