The Norwegian Model: What we can learn from modern threshold training
In this All Hours blog, we will be discussing the “Norwegian Model” made popular by Jakob Ingebretsen and triathletes Kristian Blummenfeldt and Gustav Iden. The model emphasizes the importance of high volume threshold training; it’s been a staple principle for a long time, but the Norwegian Model has put it into the spotlight. Here is an article that discusses in depth the intricacies of “lactate guided threshold interval training” colloquially known as the Norwegian Model.
Terminology
Before analyzing the Norwegian Model, we must establish what “threshold” training actually means. There are many words that are used interchangeably when discussing threshold in endurance training.
There are two physiological thresholds that I will focus on here: aerobic threshold and lactate threshold. The first, aerobic threshold (AT), denotes the point at which lactate begins to rise from baseline. Some other common words for this intensity include:
- LT1
- Steady state
- Tempo
- Jack Daniel’s marathon pace
- Sub T
- FatMax
- VT1
As you can see, a consolidation of terms or common glossary is desperately needed. AT is typically associated with a blood lactate concentration of approximately 2.5 mMol (more on this later). Aerobic threshold is a “pace” that one can hold for multiple hours, and if metabolism was the only limiting factor, they could theoretically keep indefinitely.
The anaerobic threshold, or lactate threshold (LT), denotes the point at which lactate will spike exponentially following subsequent increases in intensity. This is also referred to as:
- LT2
- Threshold
- VT1
- Maximal lactate steady state
This occurs at a blood lactate concentration around 4.0 mMol. Anaerobic threshold usually occurs at a “pace” that one could hold for 45-60 minutes. There are plenty of nuances within these statements that I won’t expand on here. One being that AT and LT are intensities, measured by blood lactate concentration, not discrete paces. Therefore, depending on how long you are running at AT/LT, the speed you are running can fluctuate. For example, an athlete might be able to run 5xmile in 4:50 at LT with a lactate concentration of 4.0 mMol. But they also might be able to run 20x400 in 67 seconds at LT with the same lactate concentration of 4.0 mMol. We can see that threshold interval distance changes the speed at which an athlete can “run threshold.” You can go much further into the weeds on this, so reach out if you would like to chat more about this, I will spare our other readers.
There is much debate and confusion surrounding the terminology, which I am not going to get into here. I will use the terms aerobic threshold and lactate threshold to denote our thresholds going forward.
The Norwegian Model: Intricacies and Takeaways
Now that threshold training is defined, I will discuss the intricacies of the Norwegian Model and how the principles can be integrated into training. The premise of the Norwegian Model is to spend as much time as possible running aerobic or lactate threshold in order to improve one’s ability to clear and utilize lactate. Lactate accumulation is directly associated with increasing acidity in one’s muscles and bloodstream, which causes fatigue and muscle failure. The topic of fatigue could be a whole book, but we will keep it at this for now. Lactate threshold is a key determinant to performance (Joyner, 1991), and is more malleable than other physiological factors like VO2 max. It has also been suggested that a high lactate threshold may be more important for race performance than a high VO2 max (Jones et al, 2021) Therefore, it makes sense to spend more time improving our threshold paces.
As previously mentioned, both AT and LT are paces that one can sustain for quite some time, usually 45+ minutes. The Norwegian Model recognizes that at these intensities, one can accumulate a huge amount of work without overwhelming the runner. Running done at intensities faster than LT can have a large inflammatory response, which hinders recovery for a long period of time. While high intensity work is necessary, it’s a double-edged sword. Running slower than LT allows for faster recovery and better adaptations.
Because training at AT/LT is easier to recover from than high intensity work, and because training AT/LT has a high return on investment, the Norwegian Model focuses on volume accumulation at these thresholds. The Norwegian Model includes days with two threshold sessions (known to many as Double T) and upwards of 4-5 threshold sessions per week. Because the intensity of these workouts is mild, it’s attainable to do both a morning session and an afternoon session in the same day. Somathletes are monitored by measuring blood lactate to ensure proper intensity and to have more data so coaches can adjust training as needed.
In the Norwegian Model, AT and LT sessions are broken up into intervals with short rest to increase the amount of volume one can incur per session. Morning sessions are done at slightly lower lactate levels, targeting AT intensity, and afternoon sessions are more dialed into LT. These aren’t hard and fast rules, but loose guidelines from years of trial and error by the Norwegian athletes that innovated modern threshold training. Below is a sample double threshold day for a 4:00 miler to give some context into paces and volume levels:
Morning
6x1600m @ 5:10/mile w/ 60” rest
Targeting AT/2.5mMol
Afternoon
20x400 @ 70 sec w/45” rest
Targeting LT/4.0mMol
The Norwegian Model follows this type of double threshold training three times per week. This means that upwards of 35% of one’s overall training volume can be done at potent intensities. To compare, traditional western training comprises 10-15% of overall volume at intensities faster than AT.
The key is that the Norwegian Model places low emphasis on training faster than LT. As a result, they can train more at moderately hard intensities (AT/LT). The merits of the Norwegian Method are clear in theory; neither session is that “hard,” but after a training day, an athlete can accumulate 10 or more miles of work at potent intensities that correspond with desired adaptations. With this much work done at reasonably high intensities and large volumes, intensity control becomes vital to the long term health of the athlete and the desired training effect. Ideally, athletes are encouraged (by the numbers, and by their coaches) to go easier rather than harder. This challenges the traditional distance running notion that everything needs to be harder and faster for runners to get better. It also reveals the biggest risk of the Norwegian Model: when done incorrectly, going too hard for large volumes can quickly result in injury, fatigue, and burnout.
This is also what makes the Norwegian Model unique. It rewards control over pushing, it emphasizes hard, but not too hard, over sessions that put athletes in the hurt locker. When done correctly, his approach to training creates sustainability and consistency in an athlete's training, which anecdotally are the most important determinants of success and improvement in distance running. This is in stark contrast to another popular training paradigm known as “polarized training,” which emphasizes work at both ends of the spectrum. I won’t go into much detail, but here is a good paper identifying and discussing the polarized model. I’m not here to say one is better than the other, ( both have historically worked for certain runners) it is important to understand the principles that underlie both ways of training. High intensities come with more injury and burnout risk, and perhaps the Norwegian Model is a “goldilocks” solution that allows for a more low-risk, high-reward training.
Conclusions
A pillar of my training philosophy is that training should be planned and executed to meet the demands of our goals or events. There is no one-size-fits-all plan for endurance training. But after seeing the success that the Norwegians and many other adopters of the Norwegian Model have had, it warrants an analysis. The underlying principles are more important to consider rather than adopting a “copy and paste” approach. For example, one of my takeaways from the Norwegian Model is understanding the importance of accumulation of volume at AT and LT. This doesn’t always have to be done by following the Norwegian Method exactly, or by doing “double threshold” all of the time, but AT/LT development can be given the emphasis it deserves.. We also can likely do more work at AT/LT than previously thought. There are also plenty of nuances not discussed here that are crucial to understand before implementing this type of training effectively, so if you would like to learn more check out the articles linked, here is one more!
Thank you for reading. Reach out with questions at owen@afterhoursathletics.com, I’d love to chat about this, and let me know what you think!
