For access to all of our training, gear, and race coverage, plus exclusive training plans, FinisherPix photos, event discounts, and GPS apps, sign up for Outside+.
Let’s face it, Norwegian triathletes have been making headlines, breaking records, and turning heads for some time now—and while their training methodologies have been analyzed and examined before, this article, published last week by Olympian, doctor, and coach Marius Bakken, lifted the lid on the Norwegian model of training, explaining exactly what they’re doing and how they’re doing it. Note: it’s no walk in the park, but it’s smart—very smart—and there are key principles relevant to all endurance athletes.
First, the obvious question. Norway? The country with about the same population as South Carolina? What and also why? A revelation over the last few years has been the ascendance of Norwegian endurance superstars both in triathlon and on the track. When it comes to multisport, we’ve been seeing the Norwegians stealing more and more of the limelight, what with Kristian Blummenfelt’s emphatic gold medal-winning performance at the Olympics and Gustav Iden’s dominance over the 70.3 distance—and that’s before we even mention both athletes’ Ironman debuts (Iden went 7:42 at Ironman Florida last year and Blummenfelt clocked 7:21 at Cozumel). And on the track, the Ingebrigtsen brothers are lighting it up too, highlighted by Jakob’s 1500 meter gold medal at the Olympics. That’s layered on Norway’s historical dominance of winter Olympic sports like cross-country skiing. So what unites the athletes across the sports?
There seems to be a strong argument that it’s how physiologists have been instrumental in helping guide training theory, which is especially evident in cross-country skiing (full article here). For example, a 2021 study in the Frontiers in Sports and Active Living journal examined the training characteristics of 12 world-class male long-distance skiers training for events that were several hours long, finding that nearly 90% of that training was lower intensity (zone 1 in a 3-zone model), with higher intensity training following strict protocols that limited fatigue accumulation. One of the more interesting variables for cross-country ski training is that blood lactate levels are monitored throughout training to dial in precise intensity levels. Interestingly, this is mirrored in the hugely polarized approach to training that we saw in this analysis from exercise physiologist and tri coach Alan Couzens when he looked at the final 90 days of Iden’s run training going into Ironman Florida at the end of last year. In short, the easy days are so very easy (and there’s a lot of them)—yet the hard days are exceptionally hard. (Note: the training theory we will talk about below involves a much higher proportion of zone 2 training.)
Beware lactate, be vigilant
A 2019 study in the International Journal of Sports Science and Coaching shows the same vigilance about lactate levels for the Ingebrigtsens. In a recent podcast with Scientific Triathlon, Coach Arild Tveiten relays information about similar intensity control for Blummenfelt. While the Norwegian principles are exciting, they are not new, in Norway or around the world. Dr. Bakken describes writing about them in the late 1990s. Coach Renato Canova has relied heavily on controlled intervals and a focus on lactate threshold for decades, and back in 2000 Dr. Bakken provided an overview of Kenyan training principles that looked similar. The Norwegians may not be reinventing the wheel (and they wouldn’t argue that they are), but they do deserve massive credit for refining the design of the wheel to a science that has implications for all athletes.
Some disclaimers before we kick this off. It’s uncertain how well these principles apply to athletes that aren’t at the far right of the bell curve for genetic talent (like Iden and Blummenfelt), particularly in running, which has a higher biomechanical/neuromuscular input than a sport like cycling. There could be differing responses based on specific genetic differences, particularly muscle fiber typology, which will impact aerobic and metabolic processes. Aging athletes or those that are VO2 max or training volume-limited may need a heavier emphasis on intensity or speed. Sex differences might be relevant too, particularly in how well a blocked workout design functions given how it impacts sex hormones, cortisol, and energy availability.
Finally, whenever talking about endurance sports, it’s important to acknowledge the elephant in the room: substances that can alter the way physiology responds to intense training (we’re intentionally not saying performance enhancing drugs, given the numerous revelations over the years that sometimes athletes take gray-area substances for supposed performance benefit).
Whatever causes someone to be an outlier, it’s important to keep in mind that you should be 99% curiously excited while retaining a right to be 1% cautiously skeptical, in order to avoid making erroneous conclusions. That final disclaimer was brought to you by someone who first learned about cycling training theory from a book on Lance Armstrong. It was like learning about sex by reading a book that described the programming language for a vibrator.
For simplicity, we’ll break this down into three key principles from Bakken’s article and other sources. The specifics are immensely complicated, so be sure to read that article for more.
3 Key Principles
Principle One: Athletes control intensity using lactate monitoring, with a higher concentration of easier threshold training than some other approaches, layered on top of high aerobic volume.
Before getting into how lactate monitoring is used, a quick primer. A seminal 2006 study in the Scandinavian Journal of Medicine & Science in Sports was instrumental in classifying the intensity ranges used in subsequent studies. A general summary of the three zones:
- Zone 1: under the first ventilatory threshold, or 2 mmol of lactate (think very easy training up to more steady running for advanced athletes)
- Zone 2: between the first and second ventilatory thresholds, generally between 2 and 4 mmol of lactate (think steady effort to traditional threshold, or approximately one-hour effort)
- Zone 3: above the second ventilatory threshold (think faster intervals and higher intensity)
The key element here involves the lactate concentrations. To simplify it a ton, lactate is produced as our bodies use glucose to fuel ATP production during glycolysis. Lactate is a fuel source for cells, and it’s accompanied by a hydrogen ion that changes muscle pH and contributes to fatigue. A 2018 review in Cell Metabolism described the lactate shuttle where the cells use lactate for energy. If this shuttling mechanism is overstressed, lactate levels and fatigue rise and exercise becomes less sustainable. A great overview by Dr. Howard Luks is here.
The Norwegian model as outlined by Bakken involves consistent lactate monitoring. Dr. Bakken found that levels around 3.0 mmol or lower were ideal to optimize his response, and some Kenyan runners were as low as 2.0 mmol during threshold intervals. By avoiding over-stressing the body, athletes can do a higher quantity of intervals and work on that lactate shuttling mechanism more effectively. That’s key for performance at all distances because it is the foundation of how the body produces energy at more intense (but still largely aerobic) outputs, from a few minutes on up. Plus, there are added benefits for injury prevention, the nervous system, and the endocrine system. These intensity-controlled intervals are layered with big weekly training volumes, with variance based on the athlete.
An athlete who diligently follows the Norwegian model could almost always do their intervals faster. But by going faster, they’d be neglecting or reversing some of the potential aerobic benefits, particularly those involving lactate shuttling and aerobic development. That’s supported by an amazing 2019 study in the Journal of Strength and Conditioning Research that looked at 85 elite athletes over their first seven years of serious training, which found that easy running volume, short intervals, and tempos had the highest correlation with long term growth. Meanwhile, longer intense intervals had the lowest correlation. In an article summarizing those findings, we concluded: “During long intervals, athletes may be tempted to make each individual effort like a little race, which may lead to fewer beneficial long-term adaptations.” Trying to use the Norwegian model but going too hard would likely end in disaster.
The exact method of using sustainable threshold intervals becomes very complicated in practice. A pro athlete with a massive aerobic base may find that their lactate threshold and aerobic threshold are compressed–that’s how a champion marathoner can go so fast for just over two hours. Thus, their threshold intervals may be lower lactate but still really fast, like the Kenyan athlete example. A less aerobically developed athlete may be higher lactate but relatively slow on threshold intervals relative to their 5K speed.
While lactate monitoring is the only true way to apply the Norwegian approach, doing finger pricks for all athletes isn’t always practical. Instead, it’s sometimes better to to focus on cues–primarily one-hour effort, half-marathon effort, controlled breathing, no muscle burning, etc., particularly after an athlete develops their speed. For more information, we sometimes do a Joe Friel-style lactate threshold heart rate test–a 30-minute hard effort, with the average heart rate of the last 20 minutes approximating LTHR (lactate threshold heart rate), with threshold intervals capped at around five beats per minute less that that in advanced athletes (adjusting based on how they feel).
Another principle from Dr. Bakken is that it’s often better for lactate levels to rise gradually during a workout. So when doing workouts, it may be ideal to ease into the effort. We’ll often have our athletes do relaxed longer intervals with a speed finish on shorter intervals or hills, particularly for athletes that are speed-limited. An example might be 8-10 x three minutes around threshold effort with one minute easy recovery, followed by five minutes easy, then 5 x 20-30 second fast hills.
All that said, a lactate test and monitoring would be best. It takes discipline and confidence to avoid grinding yourself into fine dust on workouts.
Principle Two: Higher intensity work is used for specific adaptations.
The focus on very controlled threshold training brings up the conundrum: how do slower intervals prepare an athlete to go really freaking fast? How can a 1500 meter Olympic champion do so much interval work that is substantially slower than race pace?
The answer gets back to how the body actually generates and uses energy during high intensity events. The same lactate/pyruvate processes are key, just at higher lactate levels. So optimizing those processes should improve all performance. But that still leaves the problem of developing mechanical adaptations to actually put out that power when it counts, plus the specific adaptations to sustain that power. We don’t care about the checks that the heart, lungs, and cells can write if the leg muscles and neuromuscular system can’t cash them.
The Norwegian model outlined by Dr. Bakken still includes top-end output work–primarily involving fast strides and short hills (similar to Lydiard models). A sample week in the article had two threshold days (with two workouts on each day, which will be the subject of the next point) and one hill day involving 20 x 220 meter harder hills at 8 mmol lactate, and a speed day with shorter sprints/strides. Races likely play a big role in specific adaptations as well.
It doesn’t take a massive amount of high-intensity intervals to develop speed and power. As Dr. Bakken said in the article, “the mechanical ‘speed’ you are running will always at one point or the other be majorly be limited by the aerobic abilities.” In other words, what feels like a speed limitation is often an aerobic limitation.
You don’t need to train fast all of the time to train fast when it counts. However, many professional athletes are naturally fast, or have genetics that want to go fast with the smallest amount of reinforcement. That’s my big issue with MAF training for example, where athletes are capped at a certain low intensity on almost all running–most of the people that have excelled with that type of approach are genetically gifted and have the time/physiology to handle high-volume, so that focusing almost solely on the aerobic system still leads to very fast paces. For all athletes, it’s likely key to keep up close-to-max output across some swim, bike, and run sessions, like the Norwegians.
The big question about applying the Norwegian model to non-outlier athletes is whether it can be used to get fast if that skill has not already been developed, or as an athlete ages. Many athletes probably need to develop their velocity at VO2 max as well (a higher intensity level than threshold), at least initially in their athletic trajectory, to make the threshold training correspond with faster paces (with the musculoskeletal, neuromuscular, and biomechanical systems being the main limiters, rather than the aerobic system). Bike coaches like Matt Bottrill include a good amount of VO2 max work (or “microburst” intervals of 30 seconds or so) in their cycling programs in a bid to achieve this. A beginner doing super slow thresholds relative to their possible genetic potential will not have fantastic outcomes unless they can handle a massive quantity of work. But if that same athlete first develops their speed, an increased focus on threshold training may have optimal outcomes later. The same goes for an aging or volume-limited athlete that may not be getting adequate adaptation stress.
Principle 3: Block workout days are a key part of optimizing the response to lactate-controlled training.
Here’s the big, sexy point: double threshold workout days. While “double days” are nothing new in the endurance world (and are often used to help increase overall volume/mileage for triathletes while minimizing injury risk/overload), it’s not often we hear of two threshold workouts in a day. The typical pattern (for triathletes, anyway) is volume in session one, speed work in session two.
Dr. Bakken describes a fascinating experiment to see how to get the best response from threshold training. Intervention 1 involved 7-10 days with controlled threshold sessions. Intervention 2 involved massive amounts of threshold work in a single session, something like 80+ minutes. Intervention 3 involved blocking the threshold work into a two-a-day approach. What’s really interesting here is that, for him, intervention 3 won in a landslide.
These twice-a-week double-threshold days are an X factor for the Norwegian model. Similar in some ways to Canova’s block workouts, these threshold days involve morning and afternoon workouts with threshold intervals. The idea is that this approach involves the most time at the threshold sweet spot, without accumulating excessive muscular fatigue that makes the sweet spot require slower paces to finish workouts (or increasing injury risk). There may be other adaptation benefits as well, possibly related to the complex interaction of physiology, genetics, and hormone pulses during the day.
The exact methods for double threshold days have a lot of variance based on the sources we have looked at over the years. In some approaches, one of the sessions is harder–either at a higher lactate level or more volume. In others, it’s distributed evenly. Usually, athletes do intervals rather than tempos to control lactate accumulation and avoid excess muscular fatigue, though we often use tempos for athletes who are volume- or time-limited.
One example from the article involved 6-minute intervals in the morning at a slightly lower lactate (1-minute recoveries), and slightly more intense 1-minute intervals (30 seconds recovery) in the afternoon. A similar example from the Ingebrigtsens was 5 x ~6 min with 1 min. recovery at 2.5 mmol lactate in the morning and 25 x 400 at 3.5 mmol lactate with 30 seconds recovery in the afternoon. Remember, this workout style involves very controlled intervals for these athletes. While that looks daunting, threshold work should feel pretty comfortable and controlled.
Double workouts are a cool training wrinkle that can have outsized benefits for an athlete that properly controls their efforts. An athlete should probably not try double workouts until they can do consistent easy doubles in a healthy and sustainable way. It’s also likely that an athlete needs to be doing relatively high training volume for this type of approach to not cause injury or risk over-stress. And be extra careful with potential endocrine impacts–there’s a chance that this type of training intervention is less effective (or even counterproductive) for some female athletes.
Dr. Bakken’s article has so many other brilliant tidbits, so definitely give it a full read. As with all training theory, there is no exactly right answer for everyone. But the Norwegian model’s principles are likely relevant to all endurance athletes.
Keep easy days easy. Develop speed, but don’t excessively train anaerobic processes that can detract from aerobic development. Controlled intervals are often more effective for aerobic development, and you shouldn’t be racing workouts.
And as for double workouts, lactate measurements, and massive weekly training volumes? Well, your experiences may vary. But it’s exciting as hell to explore the next frontiers in training theory.
Additional reporting was contributed by Emma-Kate Lidbury.