The most popular methodology for endurance coaches is heart rate based training. Most coaches have adopted heart rate based training because it not only prepares elite athletes to perform at the top-level but it allows amateur athletes to complete an event with a low risk of injury. Heart rate zone training primarily prescribes a low heart rate zone workout for most of the training program which generally means effort levels at an easy pace. This translates into workouts that are easy on the body because they primarily keep the body moving within a natural running stride or movement. Most injury occurs at high heart rate workouts because an athlete pushes the body into zones that are strenuous and require more effort from stabilizer muscles. Amateur athletes normally do not strength train enough to sustain higher amounts of excursion causing the stabilizers to fail and create more stress on joints and tendons. The easy answer is that an athlete should strength train properly to promote good form. That is just not the case for most athletes so the second best option is to have them train within their normal range of motion.