Skip to main content

The Importance of Lactate Testing in Sports and Performance Training

01 August 2019
In fine tuning performance in competitive sports, lactate testing makes the difference, so how can testing lactate thresholds sharpen performance?

To get ahead in sports means dedication, training and a considered diet. Getting these factors right can mean the difference between winning and losing. In fine tuning achievement in competitive sports lactate testing makes the difference, so how can testing lactate thresholds sharpen performance? 

Glycolysis and energy production

Our skeletal muscles use adenosine triphosphate (ATP) as their power source, however the body can only store so much ATP and when it’s used up in short, sharp, explosive bursts of exercise it needs to make more. The normal reserves of ATP are only enough to power the muscles for around 5-8 seconds before we need to synthesise more.

If training for endurance the body needs to make more of this power source quickly.

Once stored ATP is depleted muscles then use glucose. The body breaks down glucose to produce ATP via glycolysis and in doing so produces a by-product: pyruvic acid.

There are two systems of glycolysis – fast and slow. Fast glycolysis, or the glycolytic system, produces ATP quickly, but can only do this in relatively short, intermittent episodes. It also converts pyruvic acid into lactic acid. It’s debated whether or not the build up of lactic acid leads to muscle fatigue, but either way, fast glycolysis isn’t sustainable and can only last for short periods of time. 

A more sustainable way of producing energy, is via slow glycolysis, or aerobic ATP production. This system requires oxygen to produce ATP, and is well suited to endurance training. This process produces carbon dioxide, which can also acidify the muscles along with pyruvic acid. But it also produces hydrogen, which combines with available oxygen to produce water, and helps prevent acidification and muscle fatigue for longer.

Fast glycolysis and slow glycolysis can run simultaneously until exhaustion. 

Blood Lactate

During fast glycolysis, the resulting lactic acid combines with sodium and potassium ions to create lactate. This lactate is important in supporting the body to create more ATP from glucose, however the body needs to deal with lactate quickly and process it via oxidation.

Lactate oxidation takes place in the muscles where it’s then converted into glucose and used as an immediate energy source. This also happens in the liver where it’s stored as glycogen for future use.

In order for lactate to be a useful energy production source it needs to be cleared and converted into glucose as quickly as the body produces it. When the level of lactate produced is greater than the level of lactate cleared, resulting in an increase in muscle lactate levels, you’ve reached your ‘lactate threshold’.

Why is the lactate threshold important?

Your lactate threshold equals the time at which sustainable slow glycolysis, or aerobic ATP energy production can no longer keep up with demand. This ultimately signals the beginning of the end of the growing intensity of your training session, causing you to slow down and eventually reach exhaustion.

Once you reach your lactate threshold there’s a switch from the aerobic system to the glycolytic system, helping to get you over the finish line with a sprint or final burst.

The more distance/speed/weight you can cover before this point the better so understanding your lactate threshold can make all the difference when competing. 

The importance of lactate threshold testing

Since blood lactate levels relate to how the body uses, stores and creates energy it’s especially important to understand your lactate threshold when it comes to training, performance and endurance exercise.

Whatever the sport, from long distance running and triathlon to rowing and weight lifting, elite athletes use their lactate threshold as a performance marker, similar to the VO2 max test (maximum aerobic capacity test). 

The value of reliable, consistent lactate threshold testing

Working to harness the power of lactate threshold testing is incredibly valuable for trainers and athletes. While the athlete is (usually) cycling or running in the sports performance lab blood samples are taken at regular intervals (as well as other indices such as heart rate), to test for lactate levels. Speed/power is then increased at set intervals at a set rate. Lactate threshold is reached when blood lactate levels rise by at least 1mmol/L over two consecutive intervals.

Testing offers powerful benefits if it’s carried out regularly and the results compared over time: As increased training improves performance, the amount of speed/power the athlete can produce before reaching the lactate threshold should increase and performance improve.

Using consistent and robust blood lactate testing machinery is crucial as accuracy at both low (<5mmol/L) and high (>10mmol/L) concentrations is essential. A fast and reliable instrument can ensure that results can be effectively monitored and utilised to ensure peak performance is achieved on an ongoing basis. Training in a sports lab with reliable equipment is therefore essential for regular lactate testing with reproducible, coherent and uniform results that could mean a podium finish.