Zone 2 training explained

Zone 2 is the easy, comfortable running that should make up most of your training. Here is what it does, how to find it and why most runners run it too fast.

What zone 2 is

In the Norwegian model, zone 2 is 72–82 % of your maximum heart rate. It feels comfortable: you can talk in full sentences, breathe through your nose for most of the run and finish feeling you could keep going.

What it does for you

Running at this intensity trains the systems that matter most for endurance. Your heart pumps more blood per beat, your muscles grow more capillaries and mitochondria, and you get better at using fat as fuel. These changes take months, which is why consistency matters more than any single session.

Easy running also lets you recover between hard sessions. That is what makes it possible to run threshold and interval workouts at full quality.

How much zone 2 to run

Many successful endurance athletes spend roughly 80 % of their training time in zones 1 and 2 and the rest at higher intensity. For a runner training five days a week, that usually means three or four easy runs and one or two harder sessions.

The most common mistakes

• Running too fast. Easy runs drift into zone 3, which is too hard to recover from and too easy to build speed.
• Using an age formula as the truth. Formulas can miss your real max heart rate by 10 bpm or more, which shifts every zone.
• Ignoring drift. Heart rate creeps up in heat and late in long runs. Slow down to stay in zone rather than chasing pace.
• Giving up too early. Zone 2 pace often feels embarrassingly slow at first. It speeds up as your aerobic base improves.

A note on definitions

"Zone 2" means slightly different things in different systems. Five-zone models based on lactate place it just below the first lactate threshold. Models based on heart rate reserve give somewhat different numbers. The Norwegian model is simple, well tested and works with any heart rate watch.

Common questions

What heart rate is zone 2?

In the Norwegian model, 72–82 % of your maximum heart rate. With a max of 185, that is about 133–152 bpm.

How long should zone 2 runs be?

Anything from 30 minutes to your longest run of the week. Most of your weekly volume should be in zones 1 and 2.

Why is my zone 2 pace so slow?

Zone 2 pace reflects your current aerobic fitness. It gets faster as your base improves, often over several months.