Swimmers in freestyle events can swim in whichever manner they like. Individual medley and medley relay swimmers, on the other hand, can swim in any technique other than backstroke, breaststroke, or butterfly. Swimmers should contact the wall with any part of their body after swimming through a lane length and at the end of the race. This is called "touching" and it is required by law for all swimmers regardless of age or experience. In general, more advanced swimmers can swim faster and longer if they choose to swim in a style that uses their entire body rather than just their arms or legs. For example, an individual who is very strong in the torso will be able to swim faster when they use their whole body instead of just their arms or legs. This is because more muscle mass means more speed! The same individual could also improve their times by learning how to breathe harder while swimming, which would make using your arms instead of your body during each stroke easier and more efficient.