Anaerobic exercise refers to high-intensity physical activities that are performed in short bursts, where the body's demand for oxygen exceeds the oxygen supply available. This type of exercise primarily relies on energy sources stored in the muscles, rather than oxygen from breathing. Common examples include weightlifting, sprinting, and high-intensity interval training (HIIT). During anaerobic exercise, the body produces energy without using oxygen, leading to the creation of lactic acid. This can result in muscle fatigue, but it also helps build strength, power, and muscle mass. Incorporating anaerobic workouts into a fitness routine can enhance overall athletic performance and improve metabolic health.