PDHPE HSC CORE 2 Practice Exam 2025 – Complete Preparation Guide

During aerobic exercise, the primary fuel source utilized by the body is fats. This is because aerobic exercise relies on the presence of oxygen to produce energy over an extended duration. When the intensity of the activity is moderate, the body effectively metabolizes fats as a preferred energy source.

Fats provide a dense source of energy; they are oxidized in the mitochondria during aerobic metabolism, which allows for sustained energy release over long periods of activity. As the exercise duration increases, and if performed at lower to moderate intensity, the body will increasingly rely on fat stores rather than carbohydrates.

While carbohydrates are also a critical energy source, particularly during higher intensity exercise or for quick energy bursts, the body first taps into glycogen stores (carbohydrates) and then shifts toward using fats as a fuel source in prolonged moderate-intensity aerobic workouts. Proteins serve mainly as a last resort for energy and are not a primary fuel source during aerobic exercise, as their main role is for tissue repair and growth. Vitamins do not serve as fuel sources themselves; instead, they act as co-factors in various metabolic processes.

Thus, within the context of sustained aerobic activity, fats stand out as the primary fuel source, making them essential for endurance performance and overall energy