Jon Fong is a High Performance Coach and Master Sports Scientist for Morph Performance.
Regardless if you are a newbie, competitive age grouper or elite athlete, the amount of time and effort put into training for your upcoming endurance event is pretty sizeable. It’s probably more than you can afford each week, but you still get out there and put in the mileage. Something worth considering is the effectiveness of those miles and if it’s really giving you the biggest benefit.
Good news is with lactate threshold testing, the accurate data significantly improves the quality of your training and racing. To keep things nice and simple, the following article highlights how it all works.
What is lactate and lactate threshold?
Lactate is a fuel source produced when your body breaks down glucose for energy. When training at an easy aerobic intensity, lactate is converted back into energy and it’s concentration in your blood is kept constant. This process is called lactate clearance and this ability differs for everyone.
When pushing a higher intensity, the energy required goes up and more lactate gets produced to cope with the demand. Since your body effectively clears lactate at a fixed rate, the blood lactate concentration will keep rising till it eventually goes out of control. This tipping point is referred to as the lactate threshold.
To better explain this process, try pouring water down a funnel at a steady rate. Then gradually increasing the amount being poured. The funnel can only handle a fixed volume of water passing through and will overflow once maxed out.
Why is lactate threshold important?
Lactate threshold is a performance marker that determines your output (i.e. speed or power) at the point when you stop clearing lactate. Pushing past this point not only depletes your limited glycogen stores aggressively, it also significantly reduces your muscle functionality. A classic example is going too hard at the start and blowing up in the back half of a race.
By knowing your heart rate and output at threshold, you can work out your clearance zone and it’s corresponding heart rate range. Training within this specific zone programs your body to be more efficient and improves your threshold output over time. This results in you fatiguing less on hilly courses and being able to sustain a quicker pace for longer periods of time.
Without accurate threshold data you often end up training too hard and missing out on building a bigger aerobic base. This limits your potential to improve, minimises your performance gains and runs a higher risk of overtraining.
Lactate threshold testing
Lactate threshold testing is suited for athletes of all levels and is the most accurate method of determining training intensity zones. Follow up testing tracks improvements and current data is used to develop effective race pacing strategies. This test runs for about 30 minutes (depends on the number of stages) and the workload increases with each stage till lactate threshold is achieved. Heart rate is tracked and blood lactate is measured from finger samples at the end of each stage. It’s a sub-maximal test and only requires a harder effort in the final stages.
The above graph shows the test result of a fit age-group athlete. Lactate threshold was achieved when the reading crossed 4 mmol/L (in blue) at which the measured speed was 14.11 km/h and heart rate was 174 b/min (in green).
Despite clocking a good threshold speed during the treadmill test, the early stages at lower intensities were all above 2 mmol/L (in purple). Since lactate concentrations were high and more energy was required to produce the sustainable speeds (in red), the athlete needs to spend time training in the clearance zone to effectively bring these readings down by the next test.
This next graph above shows the result of an elite endurance athlete. Notice how well lactate is cleared even at high speeds. Achieving this result is possible if you train specifically and spend time in your optimal heart rate zones.
This final graph above shows the result of a sprint distance athlete. With an evidently poor ability to clear lactate, sustaining race pace for a long period of time is not possible in an endurance event. To significantly improve lactate threshold, retraining is necessary to first establish an acceptable base level of clearance.
What to do after getting tested
Completing your first lactate threshold test will give you a pretty good idea of where your ability stands as an endurance athlete. The result serves as a baseline measurement to compare with future tests to track your improvements and trend your progress. It’s important to evaluate the test data, detail a development strategy and apply these learnings to your training plan.
Getting tested right before a big race is also useful to measure your level of fatigue. If you are not recovering well, changes can be made to your tapering process to get you racing optimally. Use the test results to put together an effective pacing strategy to perform at your best on race day.
Be wary of reports that bombard you with lots of numbers, technical jargon and don’t offer much useful information. If you have never done testing before, it helps to ask beforehand about the test results and their application with training and racing. The response you get should be pretty telling if it’s going to be good value on your investment.
With exception to lactate clearance, fat burning is another glaring weakness seen in most endurance athletes. Regular testing provides you and your coach with concrete evidence of improvement, in both short and long-term development. If you are serious about achieving peak performance, give it a try and start training smarter and racing faster.