In which heart rate zone does most fat burning occur?

Most fat burning occurs in Zone 2, which is often referred to as the "fat burning zone." This zone typically occurs at a moderate intensity where the body primarily utilizes fat as a fuel source rather than carbohydrates. When exercising in this zone, the heart rate is elevated enough to promote fat oxidation, but not so high that the body switches to using glycogen stores predominantly.

Zone 2 is characterized by training at around 60-70% of an individual’s maximum heart rate, which is sustainable for longer durations, allowing the body to effectively utilize fat for energy. This is particularly beneficial for improving aerobic capacity and endurance while promoting fat loss.

In contrast, lower intensity zones may not elevate the heart rate sufficiently to stimulate significant fat oxidation, while higher intensity zones tend to shift the primary source of energy from fat to carbohydrates, as the body requires quicker energy responses.