Zone 2 running: heart rate, pace and how to find your zone

Most watches split heart rate into five zones, from an easy warm-up to all-out effort. Zone 2 is the dullest of them and, for many trained runners, the one they spend the most time in. Here is what heart rate it means, how to work it out for yourself, and why running in it feels so slow.

Zone 2 heart rate by age

Maximum heart rate in the table is estimated with the Tanaka formula: 208 − 0.7 × age. The first zone 2 column is a share of max heart rate, for when you don’t know your resting heart rate. The second uses the Karvonen method with a resting heart rate of 60 bpm, which gives higher numbers because your own resting rate goes into the calculation.

For an individual, the max heart rate formula can be off by about 10 beats either way. If you know your real maximum from a test or a race finish, use that instead.

How to calculate your zone 2 heart rate

1. Find your maximum heart rate. A test or a hard race finish is most accurate; without one, the Tanaka formula will do.
2. Measure your resting heart rate in the morning, lying down, right after waking, for a few days, and take the average.
3. Work out your heart rate reserve: max minus resting. For a 30-year-old with a resting rate of 60, that is 187 − 60 = 127.
4. Zone 2 by Karvonen runs from resting + 60% of reserve to resting + 70% of reserve. In the example: 60 + 76 = 136 and 60 + 89 = 149.

Why everyone talks about zone 2

The zone 2 trend grew out of research on top endurance athletes. A 2015 review by Stöggl and Sperlich brings together data from Stephen Seiler and others: elite runners, skiers, rowers and cyclists spend roughly 80% of their training time at low intensity and only about 20% at high intensity.

The same review adds a caveat: this mostly describes how elite athletes train, and controlled experiments comparing different intensity distributions are few and small. So “run 80% easy” is a sensible guideline, not a proven recipe for a recreational runner training three times a week.

How to check zone 2 without a heart rate monitor

Wrist-based optical sensors are often off in the first minutes of a run and during intervals. The talk test needs no electronics. In a 2004 study by Persinger, Foster and colleagues, people on a treadmill and an exercise bike recited a standard passage as the effort increased. Whenever speaking stopped being comfortable, they were consistently above the ventilatory threshold.

For zone 2 that means: if you can say a few full sentences without stopping for breath, you are below the threshold. If you have to chop sentences into pieces, slow down, even if your watch says zone 2.

Why zone 2 pace feels so slow

• Heart rate drifts. On a long run your heart rate climbs at the same pace as your body heats up and loses fluid. Staying in the zone means slowing down towards the end.
• Hills and heat. Uphill and on hot days your heart rate is higher at the same pace. Walking a steep climb is fine.
• The formula may underestimate your max. If your real maximum is higher than predicted, formula-based zones will sit below your actual ones. A test fixes that.

To see your zone 2 running pace, time a few easy runs in zone 2 and convert them in the pace calculator. Over time, the VO₂ max calculator shows how your fitness changes from a race result.

Zone 2 in three-zone and five-zone models

Researchers often split intensity into three zones using two thresholds: below the first, between the two, and above the second. Easy running is zone 1 in that scheme. The five-zone model on watches and apps cuts the same scale finer, and its zone 2 falls in the upper part of the three-zone easy zone. So “zone 2” in a paper about elite training and “zone 2” on your watch are not necessarily the same thing.