Tools · Move
Zone 2 heart rate calculator
Your easy, aerobic range: an effort you can hold for a long time and still talk in full sentences. Add your resting heart rate for a closer estimate.
Your Zone 2
Enter your age to see your range.
Educational, not medical advice. If you have diabetes, a heart condition or another medical condition, ask your doctor or a dietitian first.
How it works, and where it falls short.
Zone 2 is easy aerobic work, below the point where lactate starts to build up in the blood (the first lactate threshold). Endurance athletes spend most of their training time at low intensities like this, because it builds aerobic fitness without much cost to recovery.
A formula can only estimate it. A lab test gives the precise answer, and two people of the same age can sit ten beats or more apart. Treat the range as a starting point and check it with the talk test: in Zone 2 you can speak in full sentences.
Heart rate also drifts with heat, a short night, caffeine and stress, so the same pace can sit higher on a bad day. That is the part px reads each morning, against your own normal.
Sources
- Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001;37(1):153–156.
- Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate; a longitudinal study. Ann Med Exp Biol Fenn. 1957;35(3):307–315.
- Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform. 2010;5(3):276–291.
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Questions
What is Zone 2 heart rate?
The easy aerobic range, below your first lactate threshold. For most people it is roughly 60–70% of maximum heart rate, or 60–70% of heart rate reserve added to resting heart rate. You can hold it for a long time and still talk in full sentences.
Why 208 − 0.7 × age and not 220 − age?
Because it fits measured maximum heart rates better, especially past forty (Tanaka and colleagues, 2001). Both are estimates. A maximum measured in a hard effort or a test is better than either.
Should this match the zones on my watch?
Not necessarily. Watches set zones in different ways: some from maximum heart rate, some from heart rate reserve, some from a threshold test. If yours differs, check which method it uses. The talk test settles it.
Tomorrow morning, already decided.
Seven days free. By this time next week, px knows your normal.