Which metabolic system yields the highest amount of ATP for working muscles?

The oxidative system, also known as aerobic metabolism, is recognized for yielding the highest amount of ATP for working muscles during sustained exercise. This system primarily relies on oxygen to generate energy, allowing for the complete oxidation of carbohydrates (glucose) and fats.

During aerobic metabolism, glucose can produce up to 36 ATP molecules through the breakdown of one molecule of glucose, while the oxidation of fats can yield even more ATP, sometimes exceeding 100 molecules for certain fatty acids. This extensive ATP production is particularly advantageous during longer-duration, low- to moderate-intensity exercise where endurance is essential, enabling muscles to perform efficiently over extended periods.

The other metabolic systems, such as the anaerobic system, phosphagen system, and glycolytic system, provide energy more rapidly or for shorter durations, yielding less ATP overall. For instance, while the phosphagen system provides immediate energy through the use of stored ATP and creatine phosphate, it only supplies enough energy for about 10 seconds of high-intensity activity. The glycolytic system also produces ATP more rapidly than the oxidative system but yields significantly less ATP per glucose molecule compared to aerobic metabolism. Consequently, while these systems are crucial for quick energy bursts or short-duration exercise, they fall short of the oxidative system's capacity