When we exercise, chemical reactions happen to provide our body with the energy it needs to move. Part of that process is to break down glucose to form the energy molecules that muscles can consume. This breakdown releases lactic acid as one of its byproducts.
So what is the lactate threshold?
When the exercise intensity is low to moderate, the body naturally clears these byproducts at the same rate that they are generated – meaning, aerobic exercise – but there is an inflection point where the body’s capacity to remove them is surpassed- anaerobic exercise – which causes an accumulation of these byproducts in the bloodstream, including the lactic acid. This inflection point is called the lactate threshold.
Everyone has a different threshold, which depends on the person’s activity level, type of training, and physique. The good news is that it’s possible to train our body to be more efficient in clearing these byproducts, thus elevating the lactate threshold and improving our endurance ability.
How to measure lactate threshold
Proper measurements can only be made in a lab or field tests. These usually involve running while gradually increasing the effort and periodically making a small cut, usually in the finger, to take a blood sample and check how the lactate levels evolve throughout the test.
However, making such tests can be quite expensive. The insights it gives might not be worth it for the everyday runner, they are more suited for competitive athletes who want to assess if the training regimen is working because for them every second of improvement counts.
For amateur runners, a good starting point is to run by feel. Usually, a scale from 1 to 10 is used to measure the perceived effort of a run. The lactate threshold is hit when you feel a perceived effort around 6 or 7. Of course, this is not an exact measure, but it is a beginning, and it will also help stimulate your sense of perceived effort, which is very important while training and on race day.
Another way to estimate the lactate threshold is by using your maximum heart rate (MHR). Measuring with precision MHR is, again, best done in a lab. But to start you can use this calculator https://www.ntnu.edu/cerg/hrmax/ to estimate it. Then when you are training, the lactate threshold is usually hit when you are running at the lower end of the heart rate zone 4 (more about heart rate zones here Heart rate zones), or around 85% of your MHR.
Benefits of improving lactate threshold
Athletes with higher lactate thresholds benefit from an improved endurance capacity since the body can function at higher intensities without entering into the anaerobic zone. This means that the body can continue to use oxygen and fat as its primary source of energy for longer, which is the best source of energy for endurance sports because the body can produce energy this way for enormous amounts of time.
When the lactate threshold is hit the body starts using carbs as its primary source of energy since this type of energy can be transformed and made available to the muscles faster. The problem is that this type of energy is less available, it will not last long and will force you to slow down because of the fatigue buildup and the accumulation of the carbs breakdown byproducts.
The key point is that for endurance sports, the faster you go while staying in the aerobic zone, the better you will perform because you can use oxygen and fat for most of the race. This is accomplished by improving your lactate threshold.
Then in race key areas where you need some explosion, like at the end of the race or in the middle if you are trying to pass other competitors, you can use your carb reserves to give you the speed and explosion needed.
How to improve lactate threshold
There is not much consensus in the running world as to how to properly improve it. Some coaches say you need to run at higher intensities with interval training, others at low intensities. The best way for beginners and intermediate athletes to start improving is to include various workout methods into the training regimen.
Zone 2 training for instance is becoming more and more researched and new training approaches used by coaches prove that training at this intensity not only helps improve the lactate threshold but also prevents your body from overtraining. In fact, training in this zone is proving to be one of the most important things in building the musculoskeletal base for every major improvement.
Other coaches like to make threshold runs, which means forcing the body to run at a pace for a medium to long duration where the body is producing slightly more or slightly less lactate acid than the capacity it has to clear it. It will force the body to work on that and become more efficient. Strategies like tempo runs, progression runs, and long splits/strides are used.
Takeaways
The higher your lactate threshold is, the better you will perform. The goal is to have a threshold as close as possible to your MHR. If you research a marathoner’s lactate threshold you see that it is very close to the MHR, which means that they can run at fast paces for a long time using only oxygen and fat as a source of energy, which lasts a very long time.
In the running community, there is no consensus around what is best for improving it. The important is to balance your training regimen with various types of runs, and not enter into overtraining.
Let’s mix up those training plans and elevate our aerobic capacity shall we?
