Zone 2 Heart Rate: What It Is and How to Find Yours
Zone 2 heart rate is 60–70% of maximum in the five-zone model most watches use. Here is how to work out yours, why lab definitions differ, and what the research on easy training says.
Reviewed by Sameer Sontakey, Co-founder and Chief AI & Algorithms Officer at Sensor Bio. ChatPPG is independent and device-neutral; it is not a Sensor Bio product.
Short answer: in the five-zone model that Polar and most sports watches use, zone 2 is 60 to 70% of your maximum heart rate. For a 40-year-old with an estimated maximum of 180 BPM, that is about 108 to 126 BPM. It should feel easy: you can talk in full sentences. This page is general information, not training or medical advice.
Zone 2 by age
These ranges use the Tanaka equation for maximum heart rate (208 − 0.7 × age), which was built from 351 studies with 18,712 people (Tanaka et al., 2001).
| Age | Estimated max (BPM) | Zone 2, 60–70% (BPM) |
|---|---|---|
| 20 | 194 | 116–136 |
| 30 | 187 | 112–131 |
| 40 | 180 | 108–126 |
| 50 | 173 | 104–121 |
| 60 | 166 | 100–116 |
| 70 | 159 | 95–111 |
To use your own age, the max heart rate calculator compares four published formulas. If you already know your true maximum from a hard race or a lab test, use that instead: every zone shifts with it.
Two definitions of "zone 2"
The term means different things depending on who is using it.
Watch zones. Polar's five zones run from zone 1 (50–60% of maximum) to zone 5 (90–100%), with zone 2 at 60–70% (Polar). Garmin, Apple and others use similar defaults, though many let you switch to zones based on heart rate reserve or lactate threshold. The full table is on the heart rate zones chart.
Lab zones. Exercise physiologists often use a three-zone model anchored to measured thresholds. In Seiler's review of how elite endurance athletes train, the low-intensity zone is work at or below about 2 mmol/L of blood lactate, under the first threshold (Seiler, 2010). That boundary sits at a different percentage of maximum heart rate in each person, so a watch's zone 2 is an approximation of it rather than the same thing.
What the research on easy training shows
Seiler found that nationally and internationally competitive endurance athletes, training 10 to 13 times a week, tend to converge on roughly 80% of sessions at low intensity and about 20% dominated by hard work such as intervals near 90% of VO2max. That is a description of how successful athletes train, not a trial showing zone 2 is best for everyone.
Easy and hard training also do different jobs. In a trial of 40 moderately trained men matched for total work, 8 weeks of 4 × 4-minute intervals at 90–95% of maximum heart rate raised VO2max more (7.2%) than long slow running at 70% of maximum or threshold running at 85% (Helgerud et al., 2007). If VO2 max is your goal, easy volume alone may not be the quickest route.
Checking zone 2 without a lab
- Talk test: you can speak in full sentences but would not want to sing.
- Drift: on a long steady session, heart rate creeps up over time at the same pace, especially in heat. Slowing down to stay in range is normal.
- Sensor: wrist optical heart rate can lag or jump during intervals and arm-heavy exercise; a chest strap is steadier at steady paces. See how wrist heart rate accuracy compares.
References
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001;37:153–156. doi:10.1016/S0735-1097(00)01054-8
- Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform. 2010;5:276–291. doi:10.1123/ijspp.5.3.276
- Helgerud J, et al. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc. 2007;39:665–671. doi:10.1249/mss.0b013e3180304570
- Polar. Heart rate zones: the basics. polar.com
Frequently Asked Questions
- What is zone 2 heart rate?
- In the five-zone model used by Polar and most sports watches, zone 2 is 60 to 70% of your maximum heart rate. In exercise labs, the easy aerobic zone is usually defined as below the first lactate or ventilatory threshold, which varies more from person to person.
- How do I calculate my zone 2 heart rate?
- Estimate your maximum heart rate (for example with 208 − 0.7 × age), then multiply by 0.60 and 0.70. For a 40-year-old that gives roughly 108 to 126 BPM.
- Is zone 2 the same for everyone of the same age?
- No. Age-based formulas give the same numbers to everyone of a given age, but real maximum heart rate and lactate thresholds vary a lot between people. A lab test, or a known maximum from hard efforts, gives a more personal zone.
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