Question

A sprinter requires large amounts of ATP for a short burst of activity. To supply this ATP, the sprinter's muscles rely on large glycogen reserves and anaerobic metabolism. Because the muscle fibers have relatively few mitochondria to generate additional ATP, fatigue resistance is also low. Conversely, marathon runners derive most of their ATP from the more efficient process of aerobic metabolism. What is the reason for the low fatigue resistance in sprinters?

1) Large glycogen reserves
2) Anaerobic metabolism
3) Relatively few mitochondria
4) Efficient process of aerobic metabolism

Answer 1

Sprinters exhibit low fatigue resistance due to their muscle fibers having relatively few mitochondria, necessitating reliance on anaerobic glycolysis which leads to faster muscle fatigue.

Step-by-step explanation:

The low fatigue resistance in sprinters is primarily due to option 3: Relatively few mitochondria. Sprinters rely on anaerobic metabolism, specifically anaerobic glycolysis, for rapid generation of ATP without the need for oxygen. This process produces less ATP per cycle compared to aerobic respiration, leading to quicker muscle fatigue. Sprinters have muscles with fast glycolytic fibers that are designed for powerful, high-tension contractions needed for short bursts, such as a sprint. These fibers can quickly hydrolyze ATP using fast myosin ATPase, but they are not efficient for prolonged activity because they tire more swiftly due to a less abundant supply of mitochondria, which are crucial for aerobic metabolism that produces more ATP with greater fatigue resistance.