The Norwegian training method is a brand, not biology

In October 2025, Siren Amelia Seiler-Viken – daughter of the same Steven Seiler who laid the foundations of polarised training – published the results of an international survey. It posed an uncomfortable question: does the “Norwegian method” as a universal scale even exist, or is it simply a regional habit that the world perceives as standard?.

What is the “Norwegian method” and why is everyone quoting it

If you listen to podcasts about endurance and longevity — Peter Attia, Andrew Huberman, Rich Roll, Iñigo San Millán — sooner or later you'll hear the phrase “Norwegian method”. This refers to a five-zone intensity scale tied to percentage of maximum heart rate:

— Zone 1: 60–72% of HRmax — Zone 2: 72–82% of HRmax — Zone 3: 82–87% of HRmax — Zone 4: 88–92% of HRmax — Zone 5: 93–100% of HRmax

It was documented and popularised by Steven Seiler in 2010, based on the practices of Olympiatoppen, the Norwegian Olympic Training Centre. It was in his work that the concept of polarised training emerged: 80% of training volume below LT1, 20% above LT2, with a minimum in the “middle”.

It genuinely worked for the Norwegians. Jakob Ingebrigtsen, a whole host of skiers and biathletes, and record-breaking results at world championships grew up on this system. Therefore, when the Western longevity discourse in the late 2010s was looking for a “scientific standard” for intensity zones – the Norwegian scale seemed like the ideal candidate.

Since then, it's been passed from one person to another like the Mendeleev table.

What did Seiler's daughter's study show?

Siren Amelia Seiler-Viken is a runner and a master’s student at the Norwegian School of Sport Sciences. Together with her colleagues, she conducted an international survey of 778 endurance sports practitioners: coaches, athletes and sports scientists from Norway, other European countries and North America. 298 of them answered questions regarding specific lower limits of %HRmax for each of the five zones.

Result:

The 47% generally uses a five-zone scale. The rest trains according to three-zone, seven-zone, or other systems. In total, the authors identified over 40 different zonal systems in literature and practice.

Norwegians are 2.7 times more likely than everyone else are specifically using five-zone. That is, it is not a “global standard” - it is a regional prevalence.

Norwegian respondents report the highest average lower bounds for Zone 2 and Zone 3. So, the “Norwegian Zone 2” in terms of heart rate actually corresponds to what in other regions is considered the upper part of Zone 2 or even Zone 3.

No differences were found between coaches, athletes, and scientists. Nor were any differences found between elite and amateur levels. The confusion is not concentrated “among amateurs”. It is global.

Cycling and running are different zones for the same heart rate

The same study revealed another interesting finding. Cyclists have the lowest average %HRmax thresholds for Zones 1, 2 and 3 across all disciplines.

The reason is simple and physiological. Cycling is a low-impact sport, allowing you to maintain a low heart rate for long periods. In real races, a cyclist spends 15–30% of the time riding at a power output of less than 25 watts—drafting, descending, coasting. Running is a weight-bearing activity, with eccentric work at every step; it is impossible to “rest passively”. This naturally raises the heart rate.

The conclusion is unknown to those who train only on one watch: when running and cycling Garmins count “Zone 2” at the same percentage of HRmax, they show different physiological states. Running Zone 2 by heart rate often corresponds to cycling Zone 1.

What does this mean in practice

If I've been hearing about the Norwegian method as a law of physics, then 2025 gives sufficient reason to reconsider.

This is not a law. It is a regional tradition that is effective in the Norwegian training system and is not necessarily transferable to an American amateur, a Ukrainian amateur, or a 50-year-old office worker. Its specific HRmax percentages are not physiological constants, but a compromise between prescription convenience and average thresholds in the Norwegian cohort.

This doesn't mean the scale is bad. It means that Norwegian figures are a starting point, not the final answer. If my heart rate during a “light aerobic” session is above 75% HRmax, this isn’t necessarily an error — I might have a high resting heart rate or be running into a headwind. If it’s below 70%, that doesn’t necessarily mean I’m “underworking” either — I might have a low maximum heart rate.

What is truly constant is physiological thresholds, LT1 and LT2. They can be measured in a test, but even they can be assessed without a laboratory – the talk test, the feeling of effort, and the pace that can be maintained for 60–90 minutes without a breakdown in condition.

Which of these is useful?

The Norwegian method is an engineering abstraction over the behaviour of real athletes. The daughter of the abstraction's author showed that the abstraction doesn't work the same for everyone. This doesn't devalue the idea of polarised training itself; it remains strong. It devalues the temptation to copy specific percentages of HRmax as a universal template.

More about the zones themselves - how to distinguish them, what the position of 14 IJSPP 2025 experts showed, how to adjust intensity without a laboratory - in A complete guide to Zone 2. This post is about one crack in the popular perception. The guide is about the whole map.

Sources

— Seiler-Viken S.A., Mentzoni F., Seiler S., Skarli S., Losnegard T. Contextualising the Norwegian Standardised Intensity Zone Framework in an International Sample of Endurance Practitioners. Scientific Reports. 2025;15:34367. DOI: 10.1038/s41598-025-17023-z

— Seiler S. What is the best practice for determining the intensity and duration of training sessions for endurance athletes? IJSPP. 2010;5(3):276-291.

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Vitaliy / Founder of life:)on