Which substrates are primarily used during aerobic metabolism to yield ADP?

The correct answer highlights the key substrates involved in aerobic metabolism that ultimately lead to the production of ATP from ADP. In aerobic conditions, the body primarily relies on carbohydrates and fatty acids as the main substrates for energy production.

Carbohydrates, particularly in the form of glycogen, are broken down through a series of biochemical reactions during cellular respiration. This process begins with glycolysis, where glucose is metabolized to pyruvate, and it continues through the citric acid cycle and oxidative phosphorylation, ultimately leading to the conversion of ADP to ATP.

Fatty acids undergo a process called beta-oxidation, which also feeds into the citric acid cycle, contributing to energy production in the presence of oxygen. This efficient production of ATP when utilizing these substrates underscores why carbohydrates and fatty acids are essential for aerobic metabolism.

Glycogen and phosphocreatine, while important for energy metabolism, are not the primary substrates used in aerobic processes. Glycogen is indeed a significant source of carbohydrates, but phosphocreatine plays a role mainly in anaerobic conditions to rapidly replenish ATP during short bursts of intense activity.

This understanding is critical for spinning instructors, who must recognize how energy systems work to effectively plan workouts and manage the intensity levels required