There are several reasons that coaches and athletes have used heart rate monitoring and feedback as a training tool. A few of the reasons include:
- Heart rate can be used as a non-invasive look into the body, a feedback system.
- In previous years, coaches and scientists have determined that heart rate can be used to estimate the various stages of energy production within the body. This knowledge can then be used to establish training zones and plans to bring about physical improvements.
- Monitors can be a gauge to limit pace...
- ...And a gauge to improve pace.
- Monitoring provides information to determine recovery rates.
Before heading into the current research, first let's define a few terms:
Lactate Threshold (LT) is the highest exercise intensity attained before a marked increase in blood lactate concentration occurs. It is often called anaerobic threshold as well. For field testing definition, lactate threshold can be defined as the pace, and correlating average heart rate, that an athlete can sustain for approximately one hour while participating in a single sport.
Ventilatory Threshold (VT) in a laboratory exercise test is the point at which pulmonary ventilation (breathing rate) increases disproportionately in its relationship to oxygen consumption. In the field, it is noted as the point where breathing turns from steady and rhythmic to heavy, labored and not as rhythmic.
VO2 max is "maximal oxygen uptake" or the maximum amount of oxygen any individual can utilize during intense exercise--maximum exercise. It is also one of the measures that determine an athlete's physical capacity.
Several of the research papers I reviewed used different protocols for testing and evaluating heart rate, LT and the other associated physical parameters. There were 30-minute time trials; intervals of 3-minutes at increasing pace or power; and 60-second and 30-second increases in pace. From the research, it appears that several different field-test protocols can be used to estimate LT and heart rate at LT.
Notice the word "estimate". In reading through the study done by Karapetian GK, et al., it was noted that even in the laboratory, graphical results of blood lactate values were visually interpreted by two trained researchers, and a third researcher reviewed differences between the first two. Of the 28 volunteers in the study, four participants' results required discussion and interpretation from the three researchers.