HIE discusses non-functional muscle mass, with non-functional defined with reference to a particular activity. Based on this line of reasoning, weight training can be counterproductive for sprinters. The muscular output used to perform 10 sets of squats is different from that used to run a sprint. The force-velocity interaction, depicted as the spot on Hill’s force-velocity curve where the activity occurs, differs substantially between sprinting and squatting. Accordingly, each produces different adaptations (specifically with regard to type I and type II muscle fibers) which offset each other functionally. Where overall fitness is the goal, different forms of exercise is what you want. But where maximizing performance in a specific mode of athletic endeavor is the objective, specificity not diversity becomes the operative instruction. Here are a couple of training techniques specific to sprinting.

Jump squats – This exercise, discussed in HIE, can help improve sprinting speed. Other weight training exercises, such as leg extension and leg curl, develop foundational strength of quadriceps and hamstrings; however, the potential for these exercises to work against sprinters increases as reps exceed 10. High load and reps lower than 5 are ill-advised when doing these exercises because shear force on the knee is excessive. Negative phase accentuation allows you to both get better training response and, by making each rep more taxing, exhaust muscle at lower weight per total number of reps. Conventional squats performed occasionally may be slightly beneficial for sprinting, but regularly performing conventional squats is more likely to diminish sprinting speed than to enhance it.