The Double Threshold Model Explained
Daniel Komen’s 7:20.67 3000m world record from 1996 is considered by many of running’s most steadfast fans to be the toughest record on the books. Or rather it was, until a 23-year-old Jakob Ingebrigtsen knocked more than three seconds off it earlier this year.
The Norwegian is no stranger to otherworldly performances: this was his third world record, and in Paris he added a second Olympic gold medal to his collection (albeit not in his betrothed 1500m). His success, divisive personality, and role as ultimate wunderkind of Europe’s fastest family have brought him much fame; but perhaps equally, they have also put his “double threshold” training model in the spotlight.
Jakob Ingebrigtsen breaks the 3000m world record
What is Double Threshold Training?
The double threshold model involves doing two threshold workouts in one day, typically twice weekly. In the case of Ingebrigtsen, he will run two threshold workouts on Tuesday and Thursday in the off-season, with Monday, Wednesday, Friday, and Sunday being reserved for easier running and strength training, and Saturday being used for hill work. Of course, there are infinite variations to this model: as long as a person is regularly doing two threshold workouts on the same day, it can be said that they are following a double threshold training structure.
That explains the use of the word double, but how about threshold? In this case, threshold refers to the lactate threshold, and the workouts used in this training model are specifically designed to improve this physiological marker.
Team Ingebrigtsen during a training session
The Lactate Threshold
Your body has many ways of creating energy, but in the broadest sense, they can all be split into two camps: aerobic (meaning with oxygen) and anaerobic (meaning without oxygen). The anaerobic system is fuelled by glucose (sugar), which is broken down into a compound called pyruvate, which then generates ATP – the energy currency of the body. Unfortunately, this process, known as glycolysis, releases protons that lower the pH of the muscles and lead to the extremely fatiguing phenomenon called acidosis. To counteract this, pyruvate is converted into lactate, which consumes protons and shuttles them out of the cells and into the bloodstream. It’s a common misconception that lactate is the enemy – it’s actually a really good thing (and is itself recycled into energy by the liver)! But, while the buildup of lactate may not be the culprit of fatigued muscles, it does correlate with the number of protons in the muscle cells. When blood lactate levels rise above a certain point, the body can’t clear it as quickly as it’s being created, meaning the protons can no longer be effectively removed. This turning point is called the lactate threshold, and if a person continues to exceed this level of effort, they will eventually experience acidosis.
Conversely, the only waste products created by aerobic metabolism are carbon dioxide and water, which are easily removed through breathing and sweating, meaning a person can create energy aerobically for as long as they have carbohydrates and fats in their body. This difference in metabolic waste products is crucial for performance and implies that athletes should train their bodies to work aerobically at a given effort for as long as possible so that they can avoid muscular acidosis. In other words, they should try to raise their lactate threshold.
A cyclist has their blood lactate levels measured mid-workout so that they can optimise their training
Consider two cars: the Honda S500 and the Bugatti Chiron. The S500 can redline at 9500rpm but tops out at 130km/hr, while the Chiron can get up to 500km/hr but can’t push above 7000rpm. While both cars can travel at 100km/hr, the S500 is far less comfortable doing so. Similarly, if you’ve exceeded your lactate threshold in a race, and your competitors haven’t, you’re going to be working so much harder to run at the same speed.
It's worth noting that, while the lactate threshold represents a kind of transition point between the aerobic and anaerobic systems¹, it’s not as if your body simply flips a switch – even as you sit and read this article, both energy systems are engaged. Rather, the lactate threshold represents a shift in the balance of energy contributions from the two systems. A person can run at this threshold for about an hour: the shorter the race, the further above their lactate threshold they will operate.²
Marius Bakken: The Father of Double Threshold
While Norway is the spiritual home of the double threshold model, it was not created by the Ingebrigtsens; that honour belongs to Marius Bakken.
Bakken was born and raised in Sanefjord, 90 minutes south of Oslo. As his running career developed, he flicked between Europe and the USA, at one point finding himself under the tutelage of Sam Bell. Bell coached Bob Kennedy – the first non-African to break 13 minutes for 5km – but could not replicate such successes with Bakken, who moved back to Norway after two years without much improvement.
Even though he was just 20 years old at this time, Bakken had already done a lifetime of experimenting on himself: he ran almost 200km a week when he was 17 and studying in Illinois; by 18 he had returned to Europe and was following the low-volume high-intensity advice of Peter Coe; by 19 he had returned to the USA to train with Bell; and by 20, he was back in Norway with his childhood coach, armed with a master’s degree, a curiosity for the lactate threshold, and almost 6000 lactate testing strips.
Over the following months, Bakken discovered that, by running slightly below his lactate threshold, he could log hundreds of quality miles with relatively low mechanical stress. Through much trial and error, he found that he could perform two double threshold days a week and one additional session of a different nature on the weekend without sacrificing his recovery. This was radically different from what his competitors were doing, as many believed that threshold pace was too far removed from race speeds to be at all beneficial in training. This may be mechanically true, but Bakken viewed his type of training as very physiologically specific.
Marius Bakken leads the 2005 World Athletics Championships 5000m final with two laps to go
“The limiting performance factor for most 5k/10 runners is the lactate threshold. Speed matters, but I believe a common flaw in the thinking is that the most specific way of training is doing work at race pace or sub-race pace,” Bakken explained in a blog post many years ago.
“Yes, from a purely mechanical standpoint this seems like a smart approach. In theory, it sounds natural to train at a speed that you need to perform at when racing.
However – the mechanical ‘speed’ you are running will always at one point or the other be majorly limited by the aerobic abilities, where the ability to run at a maximum speed at the lactate threshold is the main one.
So specific training from a more physiological standpoint, where you optimise the internal cell processes the absolute most effective way is not at race speed, which can just be done limited. Rather it is a combination of larger amounts of lactate threshold work with a fair level of total running.”
It did not take long for Bakken to see results with this new method. He went on to lower all his personal bests from 1500m and up, make two Olympic teams, two World Championship finals, and run 13:06.39 for 5000m – a mark that lasted as the Norwegian record until 2019, when it was broken by Ingebrigtsen.
Who Should and Shouldn’t Do Double Threshold Training?
There's no such thing as a magic bullet in running, and the double threshold model doesn't pretend to be one. While the method has certainly produced results for some, the fact is that most people just can’t handle it.
A normal double threshold day might involve something like 5 x 2km in the morning and 10 x 1km in the evening. If this intimidates you, good! This is way too much work in one day for most people.
It’s true that these workouts are run slower than a traditional interval session, but the sheer volume of work – more than 30km once you account for warm ups and cool downs – is too much for a regular runner, especially when you consider that proponents of this method are doing this multiple times a week. Someone like Ingebrigtsen, who has an enormous aerobic base, decades of structured training, and the lifestyle of a professional runner has no problem absorbing such a high load. Most runners aren’t so fortunate.
Threshold training is important, but the double threshold model is an extreme version of it that should only be reserved for the most extreme athletes (and maybe not even them). Yes, Ingebrigtsen won the 5000m in Paris and broke the 3000m world record later that month, but he also finished off the podium in the 1500m behind three men who have never done a double threshold day in their life. Olympic 10,000m bronze and silver medallists Grant Fisher and Berihu Aregawi have both praised the double threshold method: Joshua Cheptegei, the man who beat them to the gold, doesn’t use it.
Ultimately, each athlete has to believe in their training and develop a system that works for them. For many, that simply means acknowledging Bakken’s work but choosing to follow a different path. But for some, the double threshold system – or the “big sexy thing”, as Olympic middle-distance runner Hobbs Kessler calls it – is here to stay.
Henrik Ingebrigtsen (L), Jakob Ingebrigtsen (M), and Filip Ingebrigtsen (R) have made the double threshold model famous
¹ To be clear, by transition point, we do not mean a transition from primarily aerobic to primarily anaerobic. Running above your lactate threshold does involve a higher reliance on anaerobic metabolism relative to a slower, easier effort: however, it remains a comparatively small fraction of the total energy created in all efforts exceeding a minute in duration. While your body may be producing lactate faster than it can be cleared, the aerobic system is still running at full tilt alongside this process.
² The actual processes of anaerobic and aerobic metabolism are extremely complicated, and as such, this article provides only a crude oversimplification.