Bodybuilding is the use of progressive resistance exercise to control and develop one's musculature. An individual who engages in this activity is referred to as a bodybuilder. In competitive amateur and professional bodybuilding, bodybuilders appear in lineups doing specified poses, and later perform individual posing routines, for a panel of judges who rank competitors based on criteria such as symmetry, muscularity and conditioning. Bodybuilders prepare for competition through a combination of dehydration, fat loss, oils, and tanning (or tanning lotions) which make their muscular definition more distinct. Well-known bodybuilders include Charles Atlas, Steve Reeves, Reg Park, Arnold Schwarzenegger and Lou Ferrigno.