What is Norwegian Singles Training?

By Johanna Gretschel

The Working Person's Answer to Double Threshold

Interest in the Norwegian training system has exploded in recent years thanks to the rise of Jakob Ingebrigtsen, the two-time Olympic gold medalist whose dominance in the 1500m and 5000m has made his training approach a topic of fascination among runners and coaches.

Often referred to as the Norwegian method, double threshold training, or simply the Norwegian model, the system emphasizes frequent sub-threshold workouts within a high-volume aerobic training structure.

But while the elite version of the system involves multiple workouts per day, a modified version — Norwegian Singles — has emerged as a practical adaptation for everyday runners balancing training with work and life.

The Norwegian Method: Double Threshold Training

Although the method is closely associated with the Ingebrigtsen family and their father and former coach Gjert Ingebrigtsen, the concept was first popularized by Norwegian distance runner Marius Bakken, who competed at the World Championships and Olympics in the early 2000s.

Bakken’s approach combined high training volume with relatively low intensity, meaning athletes spent the majority of their weekly mileage running easy.

On workout days, runners complete two separate threshold sessions, designed to stay just below lactate threshold.

Understanding Lactate Threshold

Lactate threshold (LT) refers to the intensity at which lactate begins accumulating in the blood faster than the body can clear it. For most runners, LT corresponds to an effort that feels “comfortably hard” and can typically be sustained for about an hour—roughly equivalent to 10K to 15K race pace.

Once a runner exceeds this threshold and moves toward critical speed, fatigue increases rapidly and recovery time grows exponentially. To maintain the correct intensity, athletes often measure blood lactate levels during workouts, aiming to stay within a range of 2.0 to 4.5 mmol/L.

This careful intensity control is what allows them to train frequently without accumulating excessive fatigue.

How Double Threshold Workouts are Structured

In the classic Norwegian model, athletes perform two threshold workouts in a single day.

A typical structure might look like this:

Morning session

• Longer intervals

• Example: 5 × 6 minutes at threshold

• Lactate around 2 mmol/L

Evening session

• Shorter intervals

• Example: 10 × 1 km

• Lactate around 3–4 mmol/L

Because both sessions remain below true lactate threshold, athletes are able to accumulate a large volume of work near race intensity while still recovering quickly enough to repeat these sessions multiple times per week. This balance of high aerobic stimulus and controlled fatigue is the hallmark of the Norwegian system.

Norwegian Singles: A Practical Adaptation

While double threshold training works well for professional athletes, it can be difficult for recreational runners to replicate. The Norwegian Singles method emerged on online running forums as a way to adapt the philosophy to the realities of a 9-to-5 job and limited training time.

Instead of performing two threshold sessions in one day, runners complete a single sub-threshold workout every other day, alternating with easy runs.

LetsRun message board contributor James Copeland became one of the most visible proponents of this training style. In an appearance on The Physiology of Endurance Running Podcast, Copeland explained that the structure evolved from his own training constraints.

Working within a one-hour-per-day training window, he adopted a structure of three days of sub-threshold workouts and four easy days, including the long run.

His approach was also influenced by his background as a competitive time trial cyclist, where he described frequently training at a “sweet spot” intensity—a steady, controlled effort that produces strong training gains without excessive fatigue. The same concept translates well to running.

What Sub-Threshold Pace Feels Like

In Norwegian Singles training, workouts are run at sub-threshold intensity, meaning slightly slower than true lactate threshold pace. While elite athletes may use lactate testing, recreational runners typically rely on perceived effort and heart rate.

Sub-threshold intensity should feel:

• Comfortably hard but controlled

• Around 5–6 out of 10 on the Rate of Perceived Exertion scale

Within sub-threshold training sessions, interval pace can vary slightly depending on the length of each repetition. Generally, longer intervals should feel closer to marathon pace and shorter intervals may approach half-marathon pace. Because sub-threshold intensity sits in a narrow range, many runners use online calculators or training tools to estimate appropriate pacing based on recent race performances.

Meanwhile, easy days should stay no faster than roughly 70% of maximum heart rate.

Why Norwegian Singles Works for Everyday Runners

The appeal of Norwegian Singles is simple: it captures the core principle of the Norwegian system, frequent controlled threshold work, without requiring elite training schedules.

By emphasizing moderate intensity, repeatable workouts, and plenty of easy running, the approach allows recreational runners to build aerobic fitness efficiently while managing fatigue and recovery.

For runners balancing training with careers, family, and other responsibilities, Norwegian Singles offers a practical way to apply elite training principles to real-world schedules.