TRAINING AS STRIDE PRACTICE The conventional, energy-based model of running performance encourages runners to view training as a means to increase fitnessto change the physiology inside the blank vessel of body form and biomechanics. The new, stride-based model that is taking shape in the hands of the likes of Stephen McGregor suggests that training is something else entirely: It is stride practice. Every step of every run is a step in the direction of a more beautiful (that is, efficient and powerful) stride. Yes, physiology changes in the process, but such changes are not ends in themselves. They simply support the stride changes that enable a higher level of performance. For example, an increase in the muscles’ capacity to burn lactate as fuel is a physiological change that enables a runner to sustain a faster speed longer before her stride loses entropy and fatigue sets in. In other words, it is a change that lifts a fatigue-inducing constraint on the stride. Practically speaking, what does it mean to approach training as stride practice? I suggest that it is rather different from compartmentalized technique training as it has come to be known. The best way to pursue improvement in running form is not to think about how you run but rather to simply facilitate and hasten the unconscious process that produces specific stride refinements through communication between the brain’s motor centers and the muscles. There are three obvious ways to hasten this process, alluded to earlier: repetition, variation, and exposure to fatigue. Repetition The key difference between trained and untrained runners is, of course, that trained runners have done a lot of running and untrained runners have not. Thus, the research of Steve McGregor and others that demonstrates superior efficiency in the strides of trained runners is a rationale for high-mileage training, above all else. The more you run, the more time your brain and your muscles spend in collaborative communication about the problem of running efficiently, and the faster the fruits of this communication will accumulate. It takes years of training experience for any runner to develop the most beautiful stride she will ever have, but high-mileage training will accelerate the evolution. Likewise, a runner of any given level of experience will run most efficiently at a high training volume than at a low one.