NAFC Fitness Assessment Practice Exam

The correct choice refers to anaerobic exercise, which is characterized by the body’s capacity to generate energy without relying on oxygen. During anaerobic activities, the energy is produced through pathways that do not involve oxygen use, primarily through the breakdown of glucose and other substrates in processes like glycolysis. This type of exercise is typically intense and can only be sustained for short durations, making it ideal for activities such as sprinting or high-intensity interval training.

In contrast, aerobic exercise relies on the presence of oxygen to sufficiently fuel longer-duration activities, such as running or swimming at a steady pace, where the body's demand for energy can be met through cardiovascular and respiratory systems. The other terms, endurance and resistance, describe different aspects of physical fitness. Endurance exercise focuses more on prolonged activity that typically requires oxygen, while resistance training is about building muscle strength and size, which may also include anaerobic elements depending on the intensity and duration of the activity.