There are too many to count. There are dozens and dozens of basketball leagues, a few American football leagues, soccer leagues, many baseball leagues, and so on. There is no kept count of professional athletes.
the league in the football is 35
360 football clubs in 16 leagues
Association of Professional Football Leagues was created in 1946.
Association of Professional Football Leagues ended in 1948.
European Professional Football Leagues's motto is 'Great Football makes Great Things'.