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About lactate testing

Lactate testing is beneficial for anyone who is serious about their training, wants to maximise their training time, and reliably measure their fitness and improvements.

Most conventional lactate tests involve the use of a ramp test where exercise intensity increases through a number of stages, with lactate readings taking at each stage. This is commonly used to determine the lactate threshold, off which training zones are commonly given based off percentages of this lactate threshold. Using this method alone does not only fail to take into account the individual physiological differences between athletes, but also overlooks one of the most fundamental components of endurance performance, the anaerobic capacity.

When we perform endurance exercise below anaerobic threshold much of our energy expenditure will be fuelled by fat, however, as energy expenditure increases (i.e. higher power/pace) more and more of our energy expenditure is covered by carbohydrate, until anaerobic threshold, where essentially all substrate usage is originating from carbohydrate.

A disproportionately strong anaerobic system results in high rates of glycolytic flux which will cause more glycogen and glucose breakdown, causing increased pyruvate (which turns into lactate and back to pyruvate for combustion) production at every intensity, including sub-maximal intensity. Therefore the anaerobic threshold is lowered for a given VO2Max and more carbohydrate is being used at every intensity, so time to exhaustion as well as power output/pace are decreased at the anaerobic threshold.

A high glycolytic capacity indicates a large capacity for short to medium work bouts, while a lower glycolytic capacity means lowers this ability, but increases the anaerobic threshold, while also improving recovery from efforts, and lowering carbohydrate utilisation at sub threshold intensities.

Balancing these capacities with the type of athlete and type of event is vital to determine the optimal training program and reach optimal physiology for peak performance. It is important to note that a high glycolytic capacity does not indicate the ability to put out a large amount of power in its self, but rather how much energy at any one time is being produced without oxygen. For example, we coach a cyclist with quite a high glycolytic capacity who can hardly hit 1000 watts, yet he can ride at 500 watts (well above threshold), for almost 5 minutes. By altering the training and diet to lower his glycolytic capacity, we can increase his threshold by allowing a greater proportion of his VO2max to be utilised at threshold, while also allowing him to recover faster from hard efforts. By comparison, a track sprinter may be able to hit over 2000 watts (due to differences in muscle fibre type, size etc), but with a sub-optimal (too low) glycolytic capacity, they will not be able to hold this long enough to achieve optimal performance.

The key thing to recognise is that the balance of the anaerobic and aerobic systems must be in balance for a particular athlete and particular event in order to achieve maximum performance. We need to improve and balance both systems. Push either way too far in one direction and performance will be significantly reduced due to either lowered muscle pH during efforts, or because of a lack of pyruvate for high level aerobic energy production. As uncombusted lactate ends up in the blood, we can measure blood lactate levels and use the accumulation rates and shape of the lactate curve as a measure of the strength of both the aerobic and anaerobic energy systems.

By using innovative lactate testing protocols we determine the strength of both the aerobic and anaerobic energy systems, analyse the current levels and desired levels for a particular athlete and event, and track changes to these systems over time. While metrics such as power and speed are useful measures of performance, they give no indication of how the body is producing energy, making training a time consuming guessing game, or perhaps worse if the wrong type or volume of training is prescribed.

With frequent lactate testing it is possible to determine exactly how the body is responding to training, and what changes are needed to the athletes training to allow continued performance improvement.