The concept of conditioning for baseball is no longer as new as it was even 10 years ago. But even in that relatively brief time, many methods for building athletic performance in ballplayers have been proposed and rejected.

The problem is this - baseball is a dynamic sport - no action is performed in a static position - so traditional strengthening programs (weight lifting and such) seldom work. Also while baseball depends on quick legs and powerful arms, it isn't really the arms or legs that generate all the explosive power. That power also comes from the core.