What is commonly measured with a heart rate monitor?

A heart rate monitor is specifically designed to track the number of times the heart beats per minute, which is referred to as heart rate. This metric is crucial for assessing cardiovascular fitness, understanding exercise intensity, and monitoring how well someone is responding to physical activity. By providing real-time data on heart rate, users can tailor their workouts to achieve specific training goals, ensuring they are within their target heart rate zones for optimal performance and safety.

While calories burned, body temperature, and workout duration can be monitored with other devices or technologies, they do not represent the primary function of a heart rate monitor. Therefore, measuring heart rate is the most direct and accurate use of such a device.