What type of exercise predominantly relies on the aerobic system for energy production?

Prolonged endurance activities predominantly rely on the aerobic system for energy production because they are typically performed at a steady, moderate intensity over an extended period. During these activities, such as long-distance running, swimming, or cycling, the body utilizes oxygen efficiently to produce ATP (adenosine triphosphate), which is the energy currency of the cells. This process allows individuals to sustain their efforts for longer durations without fatigue, as the aerobic system can continuously produce energy as long as there is adequate oxygen and nutrients available.

In contrast, high-intensity sprints and short-duration weightlifting primarily rely on anaerobic energy systems, which function without oxygen for quick bursts of energy over shorter time frames. Interval training includes both aerobic and anaerobic components but emphasizes periods of high intensity that challenge the anaerobic systems, making it less dependent on sustained aerobic energy production than purely endurance activities. Therefore, prolonged endurance activities stand out as the clear choice when identifying exercises that primarily utilize the aerobic energy system.