A leopards muscles are a lot quicker to react to brain signals than say a humans, this enables them to reach their top flight speed in under 30 seconds. The muscles around the leopards arteries are also very muscular so it can pump blood around the body faster. This is important as when a leopard is running it runs a real risk of starving its brain of oxygen so it is important that the oxygen carrying blood gets to the brain asap. It has a very muscular lean body, it does not have a lot of muscle but the muscle thats there is all fine tuned to do exactly as its meant to.