Conditioning for baseball pitchers has long consisted of work that is non-specific to the demands of the game. Often, what you find on baseball fields all over America is a combination of long, slow, distance work or high-intensity interval-type sprints with incomplete recoveries. Not only are these not specific to the energy system needed for the sport, but they compete with adaptive reserves that could be more useful in other processes. The following article on energy system development was written for www.simplifaster.com.