One of the most well-known scientists to explore the use of heart rate for the purpose of athletic improvement was Francesco Conconi.
His research resulted in the well-known "Conconi Test", where athletes monitor heart rate response to increases in speed. Conconi theorized that when heart rate and speed are plotted on a graph, lactate threshold occurred when heart rate no longer climbed in a linear relation to speed. He theorized that this point, named "the deflection point," was directly related to the accumulation of lactate in the body.
Currently, actual lactate accumulation in the body can only be measured by drawing blood samples. Conconi's work helped athletes and coaches utilize tools, namely the heart rate monitor, that could help athletes gauge the body's response to exercise without expensive and inconvenient laboratory tests.
Conconi and his assistants used lactate threshold information to help Francesco Moser break the World Hour Record on the bike. Conconi published his heart rate theory information, and several other scientists and coaches have based their training zones off of Conconi's theory. There have been several extrapolations of the Conconi test, and while controversy now surrounds Conconi's involvement in drug use to improve performance, his heart rate theory has remained the foundation for the work of many coaches.
Though many coaches use Conconi's work as the foundation of their training zones, not everyone agrees that Conconi's work, and the use of heart rate monitoring to improve sports performance, is valid. There is disagreement about the existence of a deflection point; the relationship between heart rate and lactate threshold; the relationship between heart rate and ventilatory threshold; and the relationship between heart rate, lactate threshold and different sport activities.
With more recent technology and research, it is worth re-examining Conconi's theory on heart rate and methods of testing.
Why Use Heart Rate as a Training Tool?
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.