National Academy of Sports Medicine (NASM) Group Fitness Instructor Practice Exam

Which statement best describes aerobic metabolism?

1. Produces ATP rapidly in short bursts

2. Maintains high levels of ATP production for longer periods of time

3. Occurs only in the absence of oxygen

4. Uses only carbohydrate as a fuel source

The correct answer is: Maintains high levels of ATP production for longer periods of time

Aerobic metabolism is characterized by its ability to produce adenosine triphosphate (ATP) efficiently over extended periods, especially during low to moderate-intensity activities. This metabolic pathway primarily utilizes oxygen to convert carbohydrates, fats, and in some cases proteins, into ATP. One of the key advantages of aerobic metabolism is that it can sustain energy production for long durations, which is essential for endurance activities like running, cycling, or swimming. The focus on maintaining high levels of ATP production for longer periods distinguishes aerobic metabolism from anaerobic processes, which tend to be less efficient and generate ATP quickly but only for short bursts of energy. These anaerobic pathways are typically employed during high-intensity, short-duration activities where energy demand spikes but cannot be sustained. Furthermore, aerobic metabolism is not limited to a single fuel source; it can utilize a combination of carbohydrates, fats, and proteins, depending on the body's availability of these nutrients and the intensity of the exercise. Therefore, the statement accurately captures the essence of aerobic metabolism in the context of energy production during sustained physical activity.