What is the range for high-intensity activity heart rate?

High-intensity activity typically refers to exercise that significantly elevates the heart rate and challenges the cardiovascular system. The range of 70% to 85% of maximum heart rate is widely recognized as the zone for high-intensity activities. This range is beneficial for improving both cardiovascular fitness and endurance, as it allows individuals to work at a level that promotes adaptations in the heart, lungs, and muscles.

At this intensity, the body uses primarily carbohydrate stores for energy, resulting in increased calorie burn and improved metabolic health. Furthermore, training within this heart rate range has been shown to enhance maximal oxygen uptake (VO2 max), which is a critical measure of cardiovascular fitness.

The other ranges presented do not align with the established definitions of high-intensity activity. The lower ranges, such as 50% to 60% and 60% to 70% of maximum heart rate, correspond more closely to moderate-intensity activity, which is beneficial for general health but does not push the limits of cardiovascular capacity as effectively as the high-intensity range. The upper range of 85% to 90% of maximum heart rate is more suited to maximal or near-maximal efforts, which may be difficult to sustain over longer periods and are typically approached in interval