What is the upper limit exercise heart rate determined by?

The upper limit of exercise heart rate is determined by calculating a percentage of the maximum heart rate. This percentage typically represents a safe yet effective intensity level for cardiovascular exercise. The choice that specifies the maximum heart rate multiplied by 0.85 aligns with the common practice of using 85% of the maximum heart rate as a guideline for vigorous exercise intensity.

This target heart rate can help individuals maintain a level of intensity that promotes cardiovascular fitness while minimizing the risk of overexertion or injury. Most training programs advocate this intensity level, especially for individuals who are looking to improve their overall cardiovascular health or performance.

The remaining options offer different methods for estimating heart rate but do not accurately reflect the established norms for upper heart rate limits during exercise, making the selection of 85% the most relevant for effective and safe fitness training.