If you watched (or heard about) Olympic gold medalist and world champion Norwegian runner Jakob Ingebrigtsen at the 2024 Paris summer games, you probably got the sense that the athlete takes his sport—and winning—seriously. “If some people can do something, I believe I can do better,” Ingebrigtsen has said.

One of his not-so-secret secrets of success? Lactate threshold training, or what some in the endurance world have dubbed the “Norwegian method” since Ingebrigtsen isn’t the only professional athlete in his country who swears by the strategy. 

“His [training] pattern has become one of the things you read about in the literature, if you start looking through Facebook or the running magazines,” says Carl Foster, PhD, a professor emeritus in the University of Wisconsin-La Crosse’s department of exercise and sport science. “Controlled lactate training is a flavor of the day.” 

But what does it actually mean—and does lactate threshold training work for athletes of all levels? Read on to find out. 

What Is Lactate?

To understand the lactate threshold, you first have to understand lactate—which, most simply, is “a normal carbohydrate molecule” produced during regular metabolic activity and exercise, Foster says. 

More specifically, Micah Zuhl, PhD, a professor in the school of health sciences at Central Michigan University, explains how lactate is created like this: If you’re cycling or running at a low-to-moderate intensity, most of your energy is coming from fat and a little is coming from carbs. The carb-burning process produces a byproduct called pyruvate, which provides energy to your cells. (This type of exercise is also considered “aerobic” since your body’s fuel is fanned by oxygen.) 

But, as you increase exercise intensity, pyruvate is converted to lactate, which the body can use in the absence of sufficient oxygen for a limited time. (Hence why this type of exercise is also called “anaerobic.”)

What Is Lactate Threshold, or Anaerobic Threshold?

The lactate threshold, then, “is often considered the inflection point between aerobic and anaerobic energy, as it’s where blood lactate (a byproduct of anaerobic respiration) starts to accumulate in the blood faster than it can be cleared,” Peloton instructor Matt Wilpers explains. That’s why the term is often used interchangeably with “anaerobic threshold.”

Semantics aside, athletes care about the lactate threshold since, broadly, it’s a marker of fitness that can be elevated through training. The higher your lactate threshold, the faster you can run (or cycle or swim) with less fatigue.

“Your pace at threshold (i.e. the pace you can hold while your body is working at threshold) is highly responsive to training, relatively easy to measure without having to go to a lab, and can be used to generate pacing guidance for your training at various intensity levels,” Matt says. “This means that as you train more and improve your fitness, you will see your pace at threshold get faster and so will your training paces.”

Focusing on training at lactate threshold “also helps you mentally get stronger by practicing maintaining a pace that is not comfortable,” Matt adds. “This helps you mentally handle harder efforts on race days.” 

How to Calculate Your Lactate Threshold 

If you’re an elite athlete or simply want to get as exact as possible with your training, you can get your lactate threshold tested at an exercise physiology lab. You can find those in most university sports science departments and some hospitals, if they house a human performance lab, Foster says. 

But there are other ways to get a good gauge of your threshold. Some companies, for instance,  sell portable lactate analyzers so you can conduct a test (including pricking your finger) on your own. While these can cost more than visiting a lab, it’s theoretically worth it since you’ll likely be testing yourself repeatedly over time in order to monitor your progress. Some research testing several of these devices, though, has found they tend to under-read lactate, which could lead to an athlete following a training plan that’s too tough. 

A more practical, though less precise, way for a recreational athlete to test their lactate threshold is through a time trial. For example, you can run for 30 minutes at the fastest pace you think you can sustain for that period of time, and track your average heart rate and how much ground you cover. That will tell you your heart rate and running speed at lactate threshold, a pace you can work to quicken over time. 

“If you ask someone to run at a hard pace, maybe even like a time-trial 5K, they will inherently run right at their threshold,” Zuhl says. “It’s almost like a survival instinct.”

What Is Lactate Threshold Training? 

Once you know what your lactate threshold is, you can develop certain workouts around it. Unlike some exercisers, who might plan their sessions with external factors like a particular pace, distance, or amount of time in mind, people who incorporate lactate threshold training use an internal factor—namely, lactate level—to guide them. 

For pro athletes, that likely means repeatedly getting a finger pricked throughout training runs in order to get real-time feedback on lactate levels. For recreational athletes, lactate threshold training may involve using other measures, like heart and breathing rate, to estimate their threshold. In both cases, the goal is to exercise just at or under your threshold in order to maximize intensity while minimizing the need for recovery.  

“The idea is to run as fast as you can, but not accumulate a lot of lactate,” Foster explains. “So you’re manipulating intensity and duration and trying to find the sweet spot where you could train your muscles in a way that’s as much like racing as possible, but you don’t cause a lot of the metabolic disturbances and discomfort that go with real high-intensity training.”

Many athletes using lactate threshold training don’t always or even mostly exercise this way, but rather incorporate it into a larger plan that includes plenty of lower-intensity activity, too, as Foster and colleagues laid out in a 2023 paper evaluating the training approaches of elite middle- and long-distance runners including Ingebrigtsen. 

When including lactate threshold training in a training plan, “people need to allocate more time for recovery, which can consist of aerobic exercise in the case of active recovery,” Matt says. “This also means that people typically cannot handle the same amount of weekly volume of anaerobic exercise vs. aerobic exercise.” 

What Does It Feel Like to Reach Your Lactate Threshold? 

While the term “threshold” may sound like it describes an absolute limit, hitting your lactate threshold doesn’t require an all-out effort. Rather, Zuhl says it should feel like you’re operating at about 65 percent intensity.  

“It feels both uncomfortable and comfortable at the same time. I sometimes refer to it as ‘weirdly sustainable,’” Matt says. “This is because it feels intense, but yet you find that you’re able to sustain it for longer than you originally thought. When you push the intensity above threshold, you know your time there will be much more limited.” 

Research has also shown that the “talk test,” or how easy it is to have a conversation during exercise, can be a decent indicator of lactate threshold. If you’re somewhere between “unsure” if you can speak comfortably and certain you can’t speak comfortably, you’re likely at your threshold. “People who are at lactate threshold can still probably have short-sentence conversations,” Zuhl says. 

How to Increase Lactate Threshold 

Whether or not you incorporate lactate threshold training into your routine, if you’re progressing in your fitness, you’re almost inevitably increasing your lactate threshold, too. “For the recreational person, your ability to train at higher intensity is always simply going to be the best way to improve these thresholds—even if you don’t know what they are,” Zuhl says. 

But if one of your specific goals is to increase your lactate threshold, there are several ways—and ideally a combination of ways—to go about it, one paper out of the University of New Mexico explains. Among them: 

1. High-Volume Training 

Upping how much you train can improve your lactate threshold. Specifically, the paper authors recommend gradually increasing your total training volume by 10–20 percent each week—meaning if you were riding your bike for a total of 100 minutes one week, the next week you could bump up to about 110. “The major benefit of increased training volume is an increased capacity for mitochondrial respiration, which is imperative to improvements in lactate threshold,” the authors say. 

2. Maximal Steady-State Training 

Maximal steady-state training involves workouts where you’re sustaining a moderate intensity without tipping above your lactate threshold. Tempo runs on the Peloton App or Tread are a good example. 

3. Interval Training 

High-intensity interval training above your lactate threshold could involve several-minute bursts of very hard intensity exercise followed by a few minutes of light-intensity exercise, on repeat. 

Varying the intensity of your workouts can elevate your lactate threshold overall, Matt says. That means you can improve by training at, above, or below your threshold—it all helps.

“Intensity can be thought of as being on a continuum … like a string. When you train at any intensity, you are pulling up at that point on the string. While your fitness at the point of intensity you are pulling up likely improves the most when you train there, your fitness at the other intensities are likely also receiving some residual benefit because they are also being elevated,” he says. “So, you can train at threshold but you can also train at other intensities as well—all will help improve your threshold.”

4. Resistance Training 

Finally, it’s helpful to add resistance training to your routine if you’re aiming towards an improved lactate threshold, Zuhl says. Any of Peloton’s strength classes should do the trick. 

Resistance training helps your body work more efficiently during exercise in part by improving how your muscles contract, he says. “So incorporating resistance exercise with aerobic exercise is really a great combination.” 

The Takeaway 

Lactate threshold training is a buzzy concept that has the potential to take some athletes’ performance from good to great. Rather than looking to external factors like pace or distance to formulate a workout, the strategy involves measuring the amount of lactate in your blood and exercising at a particular intensity accordingly. 

By training just at or under your lactate threshold—either during interval workouts or in a steady-state session—you can maximize gains while minimizing fatigue, the theory goes. 

But if you’d rather not concern yourself with the science, simply working toward any fitness goal is likely to improve your lactate threshold, experts say. “If you’re able to train consistently at higher intensities, it will naturally push your threshold to a higher point and essentially you’re able to tolerate a higher intensity of exercise for a longer period of time,” Zuhl says. “And that’s the core of performance.”