Parkinson's patient Jerry Held jumps over hoops as he works out during his Rock Steady Boxing session in Costa Mesa California, September 18, 2013. According to the Parkinson's Disease Foundation, research has shown that exercise can transiently increase the levels of dopamine in the brain, which is significantly reduced in Parkinson's disease. The club, whose headquarters is in Indianapolis, was started in 2006 and has 15 affiliates in six U.S. States, and one in Australia. REUTERS/Mike Blake (UNITED STATES)