Fundamental Concepts in Physiology Relevant to Endurance Training.
To understand endurance training it is important to have an understanding of some basic physiological concepts. Five of these principles are:
VO2 Max
VO2Max refers to the maximum amount of oxygen you can take in, transport and use when working flat out. In endurance sports, people often refer to VO2Max as a ‘pre-requisite’ for good performance – in other words, it does not determine good performance but is necessary for it. VO2Max is expressed in millilitres of oxygen absorbed per kilogram of bodyweight per minute. (mls.kg-1.min-1). In body weight supported sports such as cycling and rowing VO2Maxis expressed in litres per minute (l.min-1)
Peter Nowill (pictured) has one of the highest VO2 Max’s ever tested at the QAS. (He was a very successful 3000m Steeple Chaser and Marathon runner.
Lactate threshold (LT)
LT used to be known as “anaerobic threshold”, but this term fell out of favour because it implies that with increasing exercise intensity there is a sudden switch from aerobic to anaerobic metabolism resulting in the production of lactic acid where there was none before. In reality, even during low intensity exercise, the body produces lactate in low levels. Therefore, we often consider LT as the exercise intensity at which lactate starts to accumulate significantly in the blood.
Relationship between VO2Max and lactate threshold in endurance training
Having a good VO2Max means an endurance athlete has the potential to perform well. Being able to sustain a high percentage of that capacity with relatively low blood lactate concentration usually suggests that good performance will be a reality because there is little accumulation of muscle fatiguing lactate even at higher oxygen uptakes. When scientists test athletes in the laboratory and gather information on both current VO2Max and LT, they can express the exercise intensity at LT as a percentage of VO2 Max. The fitter an athlete becomes, the harder they can work (ie the greater percentage of their VO2Max they can use) before they reach LT point.
Fractional utilisation
The percentage of VO2Max that a person can sustain whilst exercising at race pace, dependent on both training status and exercise duration.
Maximum lactate steady state (MLSS)
The maximum steady state exercise intensity that one can sustain without a significant increase in blood lactate . Moving beyond this point would gradually take the athlete into significantly anaerobic training territory.
If you found this article interesting you may also enjoy reading Running – Chris Wardlaw’s 12 Training Principles.
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