What is the primary fuel source for aerobic exercise?

The primary fuel source for aerobic exercise is fats. During prolonged activities that rely on aerobic pathways, such as running or cycling, the body utilizes oxygen to break down fats for energy. This process is more efficient for low to moderate intensity activities, where oxygen is readily available.

Fats provide a significant amount of energy because they yield more ATP (adenosine triphosphate) when metabolized compared to carbohydrates. As the duration of exercise increases, the body will rely more on fat stores to sustain energy levels since carbohydrates (sugars) are more readily utilized during higher intensity efforts.

While sugars and proteins can also contribute to energy production, especially during different types of exercise or under various conditions, fats are considered the predominant fuel source for longer duration aerobic activities. In short, the body's preference for fat metabolism during aerobic exercise allows for sustained energy output over extended periods.