Which measurement for maximal heart rate is considered direct?

The measurement for maximal heart rate that is considered direct is the assessment that involves physically measuring heart rate during maximal effort. This method allows for an accurate and immediate evaluation of how the heart responds to intense physical activity. During this approach, an individual engages in exercise until they reach their maximum effort level, and heart rate is monitored in real-time, providing direct data on heart function and capacity.

In contrast, using a heart rate monitor provides a means to continuously observe heart rate but does not directly measure the maximum heart rate under maximal effort conditions. Calculating heart rate based on age is a formulaic approach that estimates maximal heart rate but does not reflect individual variations or the true physiological response. Observing heart rate during rest involves measuring heart rate in a non-stressed state, which does not indicate maximal capacity or performance during exercise.