There are several fitness organizations all over the world that organize competitions for the particular field of interest. In addition to organizing competitions at various levels they help promote the particular sport or event and also serve as apex bodies that lobby for and look after the interests of the participants of the sport.
Bodybuilding has numerous national and international federations that one can join in order to participate in the regular competitions and other events organized by them. National Physique Committee is the largest body building and fitness federation in the United States. They organize regular contests featuring men and women's body building and women's fitness. The International Federation of Body Builders (IFBB) is the largest federation in the world with over one hundred and fifty countries participating in their events. In the United States you have to be a member of the NPC in order to get a ranking with the IFBB.
The National Fitness Sanctioning Body is the apex organization that governs the Ms Fitness competitions. This is much more than a beauty or a body building contest and involves overall fitness including flexibility, strength and endurance.
Similarly there are martial arts organizations that are devoted to promoting various forms of martial arts. These organizations can help train those groups who are interested in acquiring particular skills and also in ranking the different styles and schools in order to introduce a degree of uniformity in all the different styles and levels.