Which of the following is true about anaerobic exercise?

Anaerobic exercise is characterized by high-intensity, short-duration activities that rely on energy sources that do not require oxygen for fuel. This type of exercise, such as sprinting or heavy weight lifting, typically lasts from a few seconds to around two minutes. During these activities, the body primarily utilizes stored glycogen in muscles for quick bursts of energy rather than burning fats or relying on aerobic processes, which operate over longer periods and involve oxygen.

The other options do not align well with the characteristics of anaerobic exercise. For instance, while carbon dioxide is produced as a by-product of both aerobic and anaerobic metabolism, the focus in this context is on the distinctive attributes of anaerobic exercise, such as the intensity and duration. Anaerobic activities are inherently brief due to the rapid depletion of energy stores, contrasting sharply with the prolonged efforts associated with aerobic exercise.