Chinese martial arts, often named under the umbrella terms kung fu, kuoshu or wushu, are several hundred fighting styles that have developed over the centuries in China. These fighting styles are often classified according to common traits, identified as "families" of martial arts. Examples of such traits include Shaolinquan (少林拳) physical exercises involving Five Animals (五形) mimicry or training methods inspired by Old Chinese philosophies, religions and legends. Styles that focus on qi manipulation are called internal, while others that concentrate on improving muscle and cardiovascular fitness are called external. Geographical association, as in northern and southern, is another popular classification method.