In the world of athletic training, heart rate monitoring is commonly utilized, but stroke volume is the preferred measure of cardiac function as heart rate is a poor measure of energy expenditure. Stroke volume is the trainable part of the cardiac function and may result in change of heart rate at rest. The figure below, shows four different types of stroke volume deviations as exercise intensity increases. In general, an increase in stroke volume as exercise intensity increases result in reaching higher intensity.
Athletes undergo stress test to deduce their fitness level, a process typically involving VO2 (oxygen consumption) and lactate threshold measurements, which provide an estimate of maximum cardiac output. providing this information in real time would result in better judgment when critical decisions are to be made. This information can provide better understanding to observe if athlete is responding to the type of training load that put upon him/her in the preparatory phase before competition period starts. During competitions, this information will provide better clue if the athlete is still progresses, whether the athlete stalls, or fatigues.