Lactate Testing, brief overview and application.
Overview of Lactate Testing
Lactate testing is in vogue in triathlon, there is no denying that. I enjoyed the meme’s of the waterfront in Kona the year Gustav Iden won, in which someone had photoshopped lactate strips covering the entirety of the sand. I think this epitomised the attention and adopting of the method at the time. This isn’t another overview article or article advocating how you MUST use lactate in your training or you can’t possibly be successful. It is simply a brief overview of the history, the method of testing and its application to hopefully give you a better understanding.
Rather than a new and groundbreaking concept, lactate measurement has been around much longer than using power or heart rate to monitor and measure effort, it was first researched in the 1920’s. It really came to prominence in the late 1990’s when George Brooks a metabolism expert from the University of California who is a leader in the field of its scientific application to sports performance revolutionised the way lactate metabolism was studied in the field of exercise physiology.
Anyone who has watched Cycling or Triathlon with commentary might be under the illusion that lactate is a by-product, lactate is actually far from a by-product, in simple terms it stands as the most crucial precursor for gluconeogenesis, the process of generating new glucose within the body. Around 30% of the glucose used during exercise originates from this process. This is a very topline explanation but hopefully helps understanding.
From all the research that exists, as a rule of thumb the higher the level of athlete the less blood lactate accumulation is observed at various intensity levels. Primarily this is because well-trained athletes are very efficient and export less lactate to the blood as they clear it in higher amounts.
So Why Lactate Testing?
Lactate testing is the best way to assess muscle metabolic stress and performance. Additionally, it stands out as the best available method for predicting performance in endurance events and serves as an excellent parameter for tailoring individual exercise training zones for athletes.
So as we've established the intensity of exercise is directly linked to an increase in blood lactate, with two significant points, (Lactate Turn Point) LT1 and LT2, where lactate levels notably rise. Running at LT1, is sustainable for approximately 3-4 hours in well-trained individuals (typically longer for cycling and shorter for swimming), can be likened to marathon or 70.3 pace. On the other hand, running at LT2, sustainable for around 30-45 minutes (usually longer for cycling and shorter for swimming), can be compared to a 10k pace or sprint distance triathlon pace.
How I use Lactate Testing
There is a huge amount of research, discussion and even terminology for zones and intensities. Hopefully this article so far has helped provide a bit of an overview. I wanted to touch upon how I use lactate measurement with athletes and what I believe are the benefits.
While estimating LT1 and LT2 by monitoring heart rate or power during cycling or running and calculating an average over a set time period (using a testing protocol MAF testing or FTP testing for example) it provides a rough gauge, it's essential to note that this method is an approximation. For precise determination of LT1 and LT2, undergoing a physiological test remains the only accurate approach.
I like to use lactate testing with an athlete primarily during the winter period, around every 6 to 8 weeks and when specifically looking at developing LT1 or LT2. Alongside monitoring power and HR the testing it gives a deeper understanding of the athletes fitness level at any given time. Typically in my experience it also produces powers or heart rate that are lower than what the athlete would achieve monitoring only power or heart rate. We can then use this whole data picture to monitor and measure training.
Testing
From the research we know longer steps typically are better, but for time efficiency and repeatability I typically would use 5 min steps. Starting with a baseline intensity and increasing the intensity every 5 mins by relatively small increments. This is easier to control and to take the lactate if in an indoor environment. The two points I am particularly looking for are the 2mmol and 4mmol which are agreed as the two thresholds, aerobic and anaerobic, LT1, LT2 or one of the many other terms that sports scientists seem to use interchangeably.
Conclusion
There are some drawbacks to lactate testing, the equipment and the testing strips are expensive. Administering the test can be difficult and there can be a high margin for error, if you’re using the results to set training intensity this can lead to errors in prescription of training. Overall though lactate testing does provide a deeper level of understanding of training intensity levels and can be a great asset in using the results to guide training alongside power and HR. If you have the opportunity to undertake testing (regular studies for University students often offer this testing for free as part of the study) it may allow you and your coach to further guide training progress and enable you to really be 100% sure that your training is targeting in the correct intensity domain to meet the demands of your target event.
Coach Jack Rees