The sport skills of kicking a football, swinging a tennis racket, shooting a hockey ball, getting air and spin on snowboards, spiking a volleyball, driving a golf ball and hitting a baseball are all dependent on a highly developed torso capable of explosive rotation.  There is a sports training paradox that most exercise professionals, with their good intention of ensuring core exercises are safe, prescribe very limited exercises that ultimately under prepare their clients for sport demands and actually set them up to be injured.
 
In the fitness world, ‘core’ strength has become a very common buzzword. In sport, you are definitely only as strong as your weakest link, and for most athletes this is the core or speed center, which includes abdominals, low back and hip musculature. For a solid base of support which is capable of transferring power through the kinetic chain, you need to build strength from the center of the body out to the periphery, as opposed to preferentially working on the muscles you can see in a mirror.