What is the primary energy pathway utilized during a marathon?

In endurance events like a marathon, the body primarily relies on aerobic metabolism to produce energy. This pathway is most efficient for prolonged physical activity because it uses oxygen to convert carbohydrates and fats into adenosine triphosphate (ATP), which powers muscle contractions.

During a marathon, which typically lasts several hours, the energy demands are sustained and require a continuous supply of ATP. Aerobic metabolism can yield significantly larger amounts of ATP compared to anaerobic processes, making it the optimal energy system for sustained efforts. It allows for steady-state energy production, which is crucial for maintaining performance over the long distance of a marathon.

Other energy pathways, such as anaerobic glycolysis, ATP-CP system, and lactic acid fermentation, are more suited to short bursts of high-intensity exercise rather than the long-duration, lower-intensity nature of marathon running. These pathways cannot provide the sustained energy output required for the duration and intensity of a marathon, as they lead to quicker depletion of energy stores and fatigue.