As has been stated previously, sprinters shouldn’t judge their need for new shoes by milage. Take into account weight lifting, plyos, and sprint work done in your shoes. The cushioning on shoes holds up much like your body does to training. If you hit it with really high intensity stuff (which is high load on your shoe cushioning) the shoes will break down. The same goes with very high volume (as in milage). In the case of sprinters, most run less than 10 a week so going on the basis of milage for replacing shoes without looking at all the harder pounding that the shoes have to take during the plyos, weights, etc. that sprinters do would be ignoring a big part of the equation.
