Interval training for cyclists inspired by the Norwegian method
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Interval training for cyclists inspired by the Norwegian method

Interval training for amateur cyclists, shaped by the Norwegian method: submaximal threshold work, lactate control, and why hard sessions stay restrained.

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Vidas Amateur Racer & Founder
· 7 min read

Interval training is the most over-prescribed and under-examined tool in the amateur cyclist’s week. The default — 4×8 or 5×8 minutes done as hard as possible, treated as the hard work of the week — is so common that most riders never question it. The Norwegian method, the framework that has shaped elite Norwegian endurance training for the last twenty years, disagrees with nearly every part of that approach.

Done its way, interval training stays controlled. The session is restrained, not crushed. The weekly dose is higher. The resulting fitness is more durable across a season, not just across a peak.

Where this approach to interval training comes from

The framework was articulated through research by Stephen Seiler, Espen Tønnessen, Leif Inge Tjelta and Øyvind Sandbakk, mostly on Norwegian world-class athletes in cross-country skiing and middle-distance running. The headline finding was that elite endurance athletes tend toward a polarized intensity distribution — roughly 80% of training time below the first lactate threshold (LT1) and 20% at or above the second (LT2), with very little spent in the metabolic middle. Seiler’s 2010 review on training intensity distribution is the canonical reference for this pattern (Seiler, 2010, IJSPP).

What made the Norwegian iteration distinctive was how the 20% gets prescribed. Threshold intervals are clamped to a target blood lactate concentration — typically 2.5–3.5 mmol/L — instead of being pushed to the highest sustainable effort. The athlete may finish a key interval session believing they could have done more. That is the point.

The submaximal principle

Sustained work at lactate levels just under maximal lactate steady state (MLSS) drives the same mitochondrial and capillary adaptations that classic threshold training targets, with one important difference: the per-session fatigue cost is lower, so the weekly volume of intervals can be much higher. Norwegian distance runners frequently complete two threshold sessions in a single day — the “double threshold” structure the Ingebrigtsen brothers made famous — at intensities that an amateur would barely register as a hard workout in isolation (Casado et al., 2022, Sports Medicine).

In cycling terms, this means the typical 5×8 minutes “as hard as you can hold” is not Norwegian-style interval training. It is a different stimulus, and it has its place — but treating every interval day as a personal best attempt is the fastest way to compress your training week into one heroic ride followed by four mediocre ones.

Doing interval training without a lactate meter

Most amateur cyclists will never measure lactate at home. That is fine. The intent of the method can be honoured with a power meter and basic discipline:

The cleanest cross-check: at the end of the session, you should believe you could have done one more rep at the same intensity. Not three more. One.

A practical interval training week

A working Norwegian-inspired interval training week for a cyclist with 7–10 hours of weekly riding looks like this:

The intervals are the named sessions, but they are not the main work — the easy hours are. A polarized distribution only functions when the easy rides stay genuinely easy, which is the most commonly violated rule in self-directed training.

Why amateurs should skip double-threshold days

Almost no amateur should attempt double-threshold days. The protocol was developed for athletes training 20–35 hours a week with full-time recovery infrastructure. The compounded fatigue from a second sub-threshold session in a single day requires a base of low-intensity volume that almost no amateur has. The benefit of the Norwegian framework for an amateur is not in stacking sessions — it is in scaling back the intensity of every individual interval session so that the cumulative weekly load is higher and more repeatable.

A useful adaptation for working cyclists: rather than two threshold sessions in one day, place two on different days with at least 48 hours of low-intensity riding between them. Total weekly time at threshold creeps up, fatigue stays manageable, and the body sees a more consistent training stimulus over months — which is the mechanism behind the published outcomes (Stöggl & Sperlich, 2014, Frontiers in Physiology).

What this asks of you

The hardest part of Norwegian-style interval training, for a self-motivated amateur, is psychological. The sessions feel modest. Strava segments do not get PR-ed on these rides. Weekly TSS often looks unremarkable. What changes is the durability of the underlying fitness over a season, and the absence of the boom-and-bust pattern that comes from training every interval day to failure.

Hard days hard, easy days easy. The Norwegian method’s contribution is in clarifying what “hard” actually means — and it is less than most amateurs assume.

FAQ

What is Norwegian-method interval training?

It is a framework — originally codified in Norwegian skiing and middle-distance running — that combines a polarized intensity distribution (around 80% easy / 20% hard) with deliberately submaximal threshold intervals. The hard work is clamped under lactate steady state instead of being pushed to failure, so the weekly volume of intervals can be higher than under classic threshold training.

How is interval training in the Norwegian method different from polarized training?

Polarized training describes the intensity distribution — low and high, very little middle. The Norwegian method specifies how the hard portion is executed: controlled, sub-MLSS, often guided by lactate measurement. All Norwegian-method training is polarized, but not all polarized training is Norwegian-method.

Do I need a lactate meter for this kind of interval training?

No. A power meter and disciplined RPE are enough for an amateur. Target 88–95% of FTP for sub-threshold intervals, keep heart rate at or below the LT2 deflection (typically 88–92% of max HR), and finish each session believing you could have done one more rep at the same intensity.

How many interval sessions per week is enough?

For most amateurs riding 7–10 hours weekly, one to two sub-threshold interval sessions per week is the right dose. The remaining hours should sit below LT1. Adding a third hard session usually erodes the quality of the others rather than producing more adaptation.

Should amateur cyclists try double-threshold interval days?

In nearly all cases, no. Double-threshold protocols rely on 20+ weekly training hours and dedicated recovery time. The same principle — controlled, repeatable threshold work — is better expressed for amateurs as two separate sub-threshold interval sessions placed 48 hours apart.

What power should Norwegian-style intervals be done at?

Roughly 88–95% of FTP, with the lower end early in a training block and the upper end later in the week. If the prescribed effort drives heart rate significantly above LT2, or you cannot complete the last rep at the same wattage as the first, the target was too high.

References