Final answer:
Anaerobic respiration helps athletes generate energy to continue running by producing ATP quickly when oxygen is scarce, despite being less efficient than aerobic respiration.
Step-by-step explanation:
When athletes run long distances and their muscles become fatigued due to lack of oxygen, the process that helps them generate more energy to continue running is B) Anaerobic respiration.
Anaerobic respiration is a metabolic process that allows cells to produce ATP without the need for oxygen.
This process is less efficient than aerobic respiration, as it produces only about four ATPs per molecule of glucose compared to the approximately 36 ATPs generated through aerobic respiration.
However, its advantage is in the speed of ATP production; it provides energy quickly for short bursts of intense activity.
When oxygen levels are low during long-distance running, the body relies on anaerobic respiration to keep muscles working.