A ‘New’ Method to Normalize Exercise Intensity

It was with interest that I read a recent article in the International Journal of Sports Medicine by KE Lansley et al. entitled, “A ‘new’ method to normalize exercise intensity” (IJSM 2011; 32: 535–541) [1]. My interest was provoked with the topic area that was very similar to research that I performed during my masters and doctoral years in the late 1970’s and early 1980’s. Far too often in peer-reviewed scientific articles I see the phrase “to the best of our knowledge” used in the introduction to supposedly verify and validate the novelty of the rationale for the research. Unfortunately it sometimes seems that the thorough search for earlier publications is not as thorough as one would hope.

Historically, Dr. Whipp was the external examiner for my doctoral research which included different studies that used the “aerobic” and “anaerobic” thresholds as a basis to explain differences in performance and adaptations to training. My research with my supervisor, Dr. James Skinner, was published in the Canadian Journal of Applied Sport Science [2] [4] (now published as the Applied Physiology, Nutrition and Metabolism Journal) and the International Journal of Sports Medicine [3] and later research using this concept was published in Medicine and Science in Sports and Exercise [5]. Specifically I would refer Drs. Lansley et al. to papers that used the aerobic threshold to establish training intensities [2] or to decrease the variability in blood lactate clearance during active recovery following high intensity exercise [3]. In addition, I would refer the authors of the current manuscript to examine papers that used both the aerobic and anaerobic thresholds to explain differences in performance [4] and blood lactate and acid-base responses [5].

I certainly would encourage the authors of the current paper in IJSM to continue to advocate the use of alternative methods to express exercise intensity. One option that we have explored recently is the use of thermal strain as the independent variable rather than %VO2max to explain cytokine and endocrine responses [6] [7]. In addition, I realize that it is not possible to have read and be cognizant of all of the literature on a particular topic and certainly the volume of literature dealing with gas exchange and blood lactate “thresholds”, critical power and the related methodology is immense. It was quite substantial when I was a doctoral student over 30 years ago so it is understandable that authors today are not aware of all of the literature that was published many years earlier. Perhaps the best advice would be to avoid the use of the phrase “to the best of our knowledge” since I would suspect that there are many topics where literature searches are perhaps not as thorough as they should be.

• References

• 1 Lansley KE, DiMenna FJ, Bailey SJ, Jones AM. A ‘new’ method to normalise exercise intensity. Int J Sports Med 2011; 32: 535-541
• 2 McLellan TM, Skinner JS. The use of the aerobic threshold as a basis for training. Can J Appl Sport Sci 1981; 6: 197-201
• 3 McLellan TM, Skinner JS. Blood lactate removal during active recovery related to the aerobic threshold. Int J Sports Med 1982; 4: 224-229
• 4 McLellan TM, Skinner JS. Submaximal endurance performance related to the ventilation thresholds. Can J Appl Sport Sci 1985; 10: 81-87
• 5 McLellan TM, Gass GC. Metabolic and cardiorespiratory responses relative to the anaerobic threshold. Med Sci Sports Exerc 1989; 21: 191-198
• 6 Selkirk GA, McLellan TM, Wright HE, Rhind SG. Mild endotoxemia, NF-κβ translocation and cytokine increase during exertional heat stress in trained and untrained individuals. Am J Physiol 2008; 295: R611-R623
• 7 Wright HE, Selkirk GA, McLellan TM. HPA and SAS responses to increasing core temperature during uncompensable heat stress in trained and untrained males. Eur J Appl Physiol 2010; 108: 987-997