Threshold training is one of the most effective workouts runners can do to build endurance and boost performance. It involves running at a “comfortably hard” effort—typically around 85–90% of your maximum heart rate—right on the edge where your body can clear lactate as quickly as it accumulates.
As both a running coach and athlete, I swear by this type of challenging workout to improve pacing consistency, top-end aerobic capacity, and race-day speed.
In this guide, we’ll break down exactly what threshold training is, the benefits it offers runners, the difference between anaerobic and lactate thresholds, and I’ll share some of my go-to threshold workouts you can incorporate into your training plan.
What Is Threshold Training?
Threshold training is a specific type of endurance workout designed to improve your lactate and anaerobic thresholds—two key markers of performance in distance running.
One of the most confusing aspects for runners is the terminology. Some sources refer to lactate threshold training, while others mention anaerobic threshold workouts.
You might see both terms used interchangeably—so, are lactate threshold and anaerobic threshold actually the same thing?
What Is The 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 threshold1Hoff, J., Støren, Ø., Finstad, A., Wang, E., & Helgerud, J. (2016). Increased Blood Lactate Level Deteriorates Running Economy in World Class Endurance Athletes. Journal of Strength and Conditioning Research, 30(5), 1373–1378. https://doi.org/10.1519/jsc.0000000000001349 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 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 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 and anaerobic thresholds overlap in terms of the percentage of your VO2 max or your running speed at which the threshold is reached.
Anaerobic threshold is a measure of energy metabolism, or how your body produces ATP (energy) for your muscles to contract.
Thus, the anaerobic threshold occurs when the exercise intensity has crossed this “threshold,” such that you can no longer produce ATP (energy) through aerobic metabolism and must now rely more heavily on anaerobic energy production.
Up until the anaerobic threshold, you are able to run or perform endurance exercise in a “steady state,“ which means that your body can rely almost entirely on aerobic metabolism to produce energy.
This means that you are getting plenty of oxygen and should be able to continue running or exercising at the same pace or exertion level for an extended period without fatigue.
The anaerobic threshold corresponds to the lactate threshold because when your body relies 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 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, 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 lactate concentration in your blood rises dramatically.
Although we used to think that the lactate, or “lactic acid,” caused this burning sensation and sudden fatigue, it has since been discovered that lactic acid does not exist as a biological molecule because it quickly dissociates from the lactate molecule.
Furthermore, it is not the lactate 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 lactate concentration 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 acidic buildup.
Many athletes lack access to continuous blood lactate testing during training, although endurance training methods like the Norwegian Method rely on blood lactate samples during lactate threshold training workouts.
Why Is Threshold Training Important for Distance 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 primary purpose of threshold training for runners is to progressively increase their lactate and anaerobic thresholds, enabling them to run faster and longer before transitioning to anaerobic metabolism and exceeding their threshold.
This is because runners and other endurance athletes have to stay at or just below the anaerobic threshold during long-duration races to maintain the same race pace and maximize their performance potential without crashing and burning.
Thus, the anaerobic threshold2Ghosh, A. K. (2004). Anaerobic threshold: its concept and role in endurance sport. The Malaysian Journal of Medical Sciences : MJMS, 11(1), 24–36. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3438148/ is the limiting factor for endurance performance.
By improving your anaerobic threshold, you can run, cycle, or swim faster in that “comfortably hard” effort level without red-lining and rapidly exhausting yourself due to the high intensity of your workout or race.
How Do I Determine My Threshold Pace?
There are different approaches to threshold training for runners and other endurance athletes.
Most threshold workouts are performed at a pace at or slightly below your anaerobic threshold (AT) or lactate threshold (LT). This pace typically brings your heart rate to about 85-90% of your maximum.
If you are accustomed to using heart rate training zones with a heart rate monitor, you can gauge your pace there.
You can also calculate your pace using a running pace calculator such as the Jack Daniels VDOT. (This will detail all your paces, including marathon pace and your other training paces.)
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, threshold workouts improve endurance performance because they allow you to run at a faster pace without accumulating fatigue.
Therefore, threshold training workouts are done at or just below the threshold.
What Are The Methods Of Threshold Training?
There are essentially two different types of threshold workouts for endurance athletes:
- Continuous threshold workouts, such as tempo runs.
- 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 continuous threshold workouts is that they build your tolerance for being “comfortably uncomfortable“ at the anaerobic threshold pace, strengthening your physical and mental ability to withstand this discomfort for a more extended period.
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. In this approach, you perform high-quality intervals at your lactate threshold pace, followed by 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, clear some of the acidic buildup, and shuttle the lactate to the liver for conversion into pyruvate.
Thus, runners can run at a faster pace using lactate threshold intervals versus continuous tempo lactate threshold runs, maximizing speed, total time, and training volume 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 often known as tempo runs. These runs are usually 20 minutes in length at your threshold pace.
Here are a couple of workouts you can try out in your training plan:
Classic Tempo (Threshold) Run
- Warm up with 10-15 minutes of easy running
- Run a 20-minute tempo run at your threshold pace
- Cool down easy for 10-15 minutes
Advanced Tempo Run
- Warm up with 10 minutes of easy running
- Run a 20-minute tempo run
- Run 10 minutes easy
- Run a 10-20-minute tempo run
- Cool down at an easy pace for 10 minutes
Threshold Interval Workouts
Examples3Bakken, M. (2022, January 7). https://www.mariusbakken.com/the-norwegian-model.html. Www.mariusbakken.com. https://www.mariusbakken.com/the-norwegian-model.html of threshold interval training workouts for runners include:
- 5 x 6:00 minutes at threshold pace with 60 seconds of recovery in between each
- 10 x 1,000 meters at threshold pace with 60 seconds of recovery in between each
- 5 x 2,000 meters at threshold pace with 60 seconds of rest between each
Add only one threshold session per week to your training plan. Starting to run at this training intensity can be tough on the body, especially if you are accustomed to running more zone 1 or zone 2 workouts. We want to avoid overtraining at all costs.
I like to schedule my speed workouts, such as threshold runs, with a recovery run, cross-training, or active recovery on either side to allow enough time for my body to recuperate for the next hard session.
After consistently incorporating threshold sessions into your running, you’ll see significant improvement as your body makes the necessary adaptations.
Let’s shave down those race times and time trials with some threshold work!
There are many types of endurance training workouts in addition to threshold training, each serving a particular physiological purpose to help improve your fitness level and performance.
To check out the different types of running workouts you can add to your training, read the following guide:
