One of the parameters clinicians most often measure during athlete performance testing and clinical exercise testing, is that of blood lactate concentration. Measuring and monitoring such a parameter is now common, not just in the sports lab, but also now in the field. This is because, in addition to lab-based analysers, portable systems are also widely available.
Why test blood lactate concentration
Blood lactate concentration measurements check for elevated levels. This measurement is useful in assessing an athlete for any underlying pathology during a routine stress test. This may be a metabolic impairment, coronary artery disease, chronic renal failure or chronic airway obstruction. Consequently, it is then helpful in prescribing the most appropriate exercise intensities. Furthermore, it is recommended that the analysis of blood lactate concentration be added to normal stress testing measurements.
Complications of concentration interpretation
When it comes to interpreting blood lactate concentration, complications arise. One such complication is due to the dramatic increase in concentration which characterises a normal response to exercise. This happens if an athlete exceeds the work rate at which the removal of lactate from the blood is as quick as it enters it. Additionally, complications will also arise because elevations of blood lactate are not necessarily indicative of an inadequate blood supply to an organ or part of the body. Nor are they indicative of an abnormally low level of oxygen in the blood. These two complications are ischemia and hypoxemia, respectively.
Reliable and accurate portable analysers
The Lactate Pro2 and Lactate Scout+ are both portable, hand-held analysers. Along with three other devices, their reliability and accuracy are put to the test in a study published in the Journal of Sports Science & Medicine. Investigators compare all devices with a criterion blood analyser, the Radiometer ABL90. This particular analyser is in use in hospitals where there is a high demand. Therefore you will find it in units such as Neonatal Intensive Care Units, Intensive Care and Emergency Departments.
The discussion finds that ultimately,
“the ideal portable analyser will depend upon the end user requirements since, in a clinical setting, the ability to measure very high concentrations of blood lactate may not be as important as for those working with elite athletes.”
Results suggest that any of the analysers tested could have a use, over time, to reliably derive blood lactate thresholds. It also suggests that any of the analysers could help to prescribe training intensities within an individual.
The investigation limits itself to a laboratory-based comparison. However, it makes it clear that using finger prick/earlobe blood sampling in the field may produce slightly different results.