Final answer:
During long races, an athlete relies more on aerobic energy production, which is compromised at high altitudes due to lower oxygen levels, leading to decreased performance in energy production for prolonged activities.
Step-by-step explanation:
During long races, an athlete needs more aerobic energy production than short races. This type of energy production is more efficient for longer durations because it uses oxygen to produce a higher amount of adenosine triphosphate (ATP), allowing the muscle to work for extended periods. At high altitudes, where there is less oxygen available, aerobic metabolism can be compromised, affecting performance and energy production.
Aerobic energy production utilizes glucose, pyruvic acid, and fatty acids, yielding approximately 36 ATPs per glucose molecule. In contrast, anaerobic glycolysis, which is more prevalent in short, high-intensity activities like those performed by a sprinter, can produce energy quickly without oxygen but only yields about four ATPs per glucose molecule and leads to quicker fatigue due to the buildup of lactic acid.
Different muscle fiber types also play a role in energy production; slow oxidative fibers use aerobic metabolism and are suited to endurance, while fast glycolytic fibers are designed for short bursts of high-intensity activity using anaerobic metabolism.