What is the intensity range for the endurance energy zone?

The endurance energy zone is typically defined as the range of exercise intensity that enhances aerobic capacity, allowing individuals to sustain physical activity for longer periods. This zone is crucial for building stamina and improving overall endurance, which is especially important for activities such as long-distance cycling or running.

The intensity range of 65-75% of maximum heart rate (MHR) is aligned with the physiological benefits associated with endurance training. At this level, the body primarily uses fat stores for fuel, improving the efficiency of both the cardiovascular and muscular systems. Exercising at this intensity encourages adaptations that enhance the ability to perform prolonged aerobic activities, which is essential for endurance athletes.

Higher intensity levels, such as those in the range of 75-85% MHR, push the body into anaerobic thresholds, where lactic acid begins to accumulate, and performance may be sustainable only for shorter durations. Similarly, lower intensity levels, such as those at 50-60% or even 60-70% MHR, may not sufficiently challenge the cardiovascular system to foster the adaptations needed for improving endurance. Therefore, the identified range of 65-75% MHR is optimal for developing endurance capabilities.