In the early 1900s, German athlete Joseph H. Pilates began experimenting with an exercise system that would assist him in his recovery from severe asthma. He designed a series of exercises to balance the body, improve ease of motion and promote mental and physical harmony. While working as a nurse, he tried to help WWI hospital patients recovering from their injuries by attaching springs to their beds, enabling them to start exercising their arms and legs even before they could walk. He went to the United Sates in 1920s and started his own studio with equipment he designed. He taught his system to dancers and used it to rehabilitate people with injuries and disabilities.