Muscle Fiber Question: Please help?? Really stuck!?

long distance runners have more of the slow twitch muscle fibers. to sustain the long distances, they need large amounts of oxygen, hence the high amounts of myoglobin. it uses the usual glycolysis and krebs to create energy. sprinters have more of the fast twitch muscle fibers, which gets its energy from anaerobic respiration--which means it does not need oxygen to function. it uses lactic acid to produce energy. but because lactic acid cannot be produced at great amounts at a time, it can only be used for activities involving sudden bursts of energy.