What is a physiological benefit of interval training?

Interval training is characterized by alternating periods of high-intensity exercise with lower-intensity recovery phases. This type of training is highly effective for enhancing cardiovascular fitness because it creates a significant demand on the cardiovascular system. During the high-intensity intervals, the heart rate increases, which strengthens the heart muscle and improves its efficiency over time. This leads to better oxygen delivery throughout the body and an enhanced ability to perform endurance activities. Additionally, studies show that interval training can boost aerobic capacity and lead to adaptations that help improve overall cardiovascular health, such as better blood flow and lower resting heart rates.

The other options reflect outcomes or characteristics not associated with the physiological benefits of interval training. For example, increased risk of injury and burnout are potential concerns but do not represent physiological benefits. Likewise, a decrease in metabolic rate contradicts the established knowledge that interval training typically increases metabolic rate, both during and after the exercise session. Thus, improved cardiovascular fitness rightly highlights a key physiological advantage of interval training.