Power, Speed, Endurance is a highly effective training system that has catapulted thousands of endurance athletes to the next level. Developed by CrossFit Endurance founder Brian MacKenzie and featuring instruction from some of the world's top endurance and CrossFit coaches,oPower, Speed, ENDURANCEounveils techniques, drills, and training strategies that will optimize your performance and overall work capacity while decreasing your susceptibility to injury.