Threshold training is one of the key running workouts to improve endurance performance.
However, some runners may not be familiar with exactly what this type of training entails and may ask: Is anaerobic threshold training the same as lactate threshold training for runners?
What are the important training thresholds for runners and other endurance athletes like cyclists and triathletes? What are some of the best anaerobic threshold training workouts for runners?
In this threshold training guide for runners, we will discuss what training thresholds are, the differences between anaerobic vs lactate threshold training for runners and endurance athletes, and how to do threshold training workouts.
We will look at the following:
- What Is Threshold Training?
- Why Is Threshold Training Important for Runners?
- How to Do Threshold Training for Runners and Endurance Athletes
Let’s get started!
What Is Threshold Training?
Threshold training is a particular type of endurance training workout that helps improve your lactate threshold and anaerobic threshold.
One of the things that’s most confusing about threshold training for runners is the fact that some sources reference anaerobic threshold, whereas others discuss lactate threshold.
For example, you might hear about lactate threshold runs or anaerobic threshold workouts.
So, are lactate threshold and anaerobic threshold the same thing? What are the differences between the anaerobic threshold vs lactate threshold?
Technically, the anaerobic threshold and lactate threshold are not the same things, but they occur around the same effort level and are characterized by similar physiological sensations.
Anaerobic threshold and lactate threshold both refer to the point at which you will feel like your effort level has gotten significantly harder even though your running pace or speed has not increased significantly.
Essentially, after either the lactate threshold or the anaerobic threshold is crossed, you will see a significant spike in the fatigue that you feel in your legs, the heaviness and burning sensation in your muscles, the rate of your breathing, and your perceived exertion.
The actual physiological metrics that are being evaluated with anaerobic vs lactate threshold are technically different, but again, what you will feel in your body is the same.
This is because the lactate threshold and anaerobic threshold pretty much overlap in terms of the percentage of your VO2 max or your running speed at which the threshold is reached.
Anaerobic threshold is looking specifically at energy metabolism, or how your body is producing ATP (energy) for your muscles to contract.
Thus, the anaerobic threshold occurs when the intensity of your exercise has crossed over this “threshold,” such that you are no longer able to produce ATP (energy) through aerobic metabolism, and you now have to rely more heavily on anaerobic energy production.
And up until the anaerobic threshold, you are able to run or perform endurance exercise in a “steady state,“ which means that your body is able to rely almost entirely on aerobic metabolism to produce energy.
This means that you are getting plenty of oxygen, and you should be able to continue running or exercising at the same pace or exertion level for an extended period of time without fatigue.
The anaerobic threshold corresponds to the lactate threshold because when your body is relying on anaerobic glycolysis to produce energy, the end product is lactate along with a hydrogen atom, which is an acid.
Below the lactate threshold, your muscles are actually able to shuttle the lactate to the liver to be further broken down to pyruvate to create ATP.
At the lactate threshold, your body suddenly shifts from being able to clear the lactate and acidic metabolic waste products at the same rate they are being produced.
This means that the concentration of hydrogen ions, which is associated with the burning feeling and immense and sudden fatigue you feel beyond the anaerobic or lactate threshold, begins to build up.
Essentially, after the lactate threshold or an aerobic threshold has been crossed, your muscles are inundated with acidic waste, and the concentration of lactate in your blood rises dramatically.
Although we used to think that it was the lactate, or “lactic acid, “ that was causing this burning sensation and sudden fatigue, it has since been discovered that lactic acid does not exist as a biological molecule because the acid quickly dissociates from the lactate molecule.
Furthermore, it is not the lactate that is causing the discomfort but the hydrogen ions.
However, because it is not really possible to measure the concentration of hydrogen ions, exercise physiologists can take blood samples and measure the concentration of lactate in the blood to serve as a biomarker of your lactate threshold and reliance on anaerobic metabolism.
Lactate concentration can be readily measured and corresponds with the amount of acidic buildup.
Many athletes do not have access to continuous blood lactate testing while training, though endurance training methods such as the Norwegian Method of endurance training does rely on blood lactate samples during lactate threshold training workouts.
Why Is Threshold Training Important for Runners?
The lactate threshold and anaerobic threshold are not necessarily important metrics that you have to know or may even have access to measuring yourself, but it is important to have a grasp of the running pace or speed at which you hit these thresholds.
The entire purpose of threshold training for runners is to progressively boost your lactate and anaerobic threshold such that you can run faster and longer before switching over to anaerobic metabolism and crossing your threshold.
This is because runners and other endurance athletes have to stay at or just below the anaerobic threshold during long-duration races in order to maintain the same pace and maximize their performance potential without crashing and burning.
Thus, for all intents and purposes, the anaerobic threshold is the limiting factor for endurance performance.
Therefore, by improving your anaerobic threshold, you can run faster, cycle faster, or swim faster in that “comfortably hard“ effort level without red-lining and rapidly exhausting yourself.
How to Do Threshold Training for Runners and Endurance Athletes
There are different approaches to threshold training for runners and other endurance athletes.
Most threshold workouts are performed at a pace that is at or slightly below your anaerobic threshold (AT) or lactate threshold (LT). This is typically a pace that brings your heart rate to about 85-90% of your maximum heart rate.
This intensity is thought to be the “sweet spot” where you can improve the efficiency of the anaerobic system and help push the anaerobic threshold higher.
Essentially, doing threshold workouts improves your endurance performance because you can run, cycle, swim, or perform some other type of endurance exercise at a faster pace without accumulating fatigue.
Therefore, threshold training workouts are done at or just below the threshold.
There are essentially two different types of threshold workouts for runners and endurance athletes:
Continuous threshold workouts, such as tempo runs or threshold training intervals, which involve running at your threshold pace for designated intervals of a specific distance or time and then taking relatively short recovery breaks.
The benefit of tempo runs and continuous threshold workouts is that you will build your tolerance at being “comfortably uncomfortable“ at the anaerobic threshold pace so that your physical and mental ability to withstand this discomfort for longer races is strengthened.
However, there is a limit to how long you can perform tempo runs or longer threshold intervals because if you cross over the threshold, you will experience that rapid accumulation of fatigue and will need a break.
Some endurance training methods, such as the Norwegian Method for runners and endurance athletes, use a lactate threshold interval approach where you perform high-quality intervals at your lactate threshold pace but then take recovery periods.
This helps you do more high-quality work in a single threshold workout session without quickly becoming exhausted or needing tons of recovery in the following days.
The rest periods in threshold interval workouts for runners allow the body time to buffer and clear some of the acidic buildup and shuttle the lactate to the liver for conversion into pyruvate.
Thus, runners or other endurance athletes can run at a faster pace using lactate threshold intervals versus continuous tempo lactate threshold runs, maximizing speed and total time and training volume done within the lactate threshold zone without crossing over into the anaerobic zone and needing to end the workout early.
Continuous Threshold Workouts
Continuous threshold workouts are tempo runs.
These are runs that are at least 20 minutes in length at your threshold pace.
Threshold Interval Workouts
Examples of threshold interval workouts for runners include:
- 5 x 6:00 minutes with 60 seconds of recovery in between each
- 10 x 1,000 meters with 60 seconds of recovery in between each
- 5 x 2,000 meters with 60 seconds of rest between each
There are lots of different types of endurance training workouts, each serving a particular physiological purpose to help improve your performance.
Check out the different types of running workouts here.