Apple Watch heart rate zones, how they are set and how to train in them
Short answer
Apple Watch splits your effort into five heart-rate zones, from easier to harder. It works them out for you from your health data as a percentage of your maximum heart rate, and only once your date of birth is in the Health app on your iPhone. To see them, start a cardio workout such as an outdoor run and turn the Digital Crown to the Heart Rate Zone view. To change them, open Settings on the watch, go to Workout, then Heart Rate Zones, tap Manual and set the limits of zones 2, 3 and 4.
How to see and change your zones
Apple's own steps, from its Apple Watch User Guide:
| You want to | Do this |
|---|---|
| See your zone during a workout | Open Workout, start a cardio-focused workout (an outdoor run, for example), then turn the Digital Crown to the Heart Rate Zone view. It shows your zone, heart rate, time in the current zone and average heart rate. |
| See time in each zone afterwards | On iPhone, open Fitness, tap Sessions, tap the workout, then tap Show More next to Heart Rate. |
| Set your own limits | On the watch, open Settings, go to Workout, then Heart Rate Zones, and tap Manual. Tap zone 2, 3 or 4 and enter the lower and upper limits. You can do the same on iPhone in the Apple Watch app, under My Watch, then Workout, then Heart Rate Zones. |
If you see no zones at all, check that your date of birth is filled in under your Health profile on iPhone.
Where zone numbers come from, worked through
Every zone model starts with an estimate of your maximum heart rate. The old rule of thumb is 220 minus your age. A 2001 meta-analysis by Tanaka, Monahan and Seals found that 208 minus 0.7 times your age fits healthy adults better, and that 220 minus age underestimates the maximum in older adults. At 60, the two give 160 and 166 beats per minute.
There are two common ways to turn that maximum into zones:
- Percent of maximum heart rate. Each zone is a slice of your maximum. Simple, but it ignores how fit you are at rest.
- Percent of heart-rate reserve (the Karvonen method). Reserve is your maximum minus your resting heart rate, and each zone sits a percentage of that reserve above your resting rate. Two people of the same age get different zones if one has a lower resting heart rate.
Here is the reserve method for a 35-year-old with a resting heart rate of 60:
- Maximum: 208 − (0.7 × 35) = 183.5, so 184 beats per minute.
- Reserve: 184 − 60 = 124.
- Each boundary: 60 + (percentage × 124).
| Zone | Share of reserve | Beats per minute | How it feels |
|---|---|---|---|
| 1 | 50 to 60% | 122 to 134 | Very easy, recovery |
| 2 | 60 to 70% | 134 to 147 | Easy, you can hold a conversation |
| 3 | 70 to 80% | 147 to 159 | Steady, talking gets harder |
| 4 | 80 to 90% | 159 to 172 | Hard, a few words at a time |
| 5 | 90% and up | 172 and up | All-out, short efforts only |
These are estimates. Your real maximum can sit well above or below any formula, so if a zone never feels right, trust how the effort feels and adjust it. The "how it feels" column follows the CDC's talk test: at moderate effort you can talk but not sing, and at vigorous effort you cannot say more than a few words without pausing for breath.
How to use your zones in a week
Most of a mixed week sits in the easy zones, with a little hard work on top:
- Easy runs, walks and rides in zone 2. This is the base of a plan like the 5K training plan: long enough to build fitness, easy enough to recover from by tomorrow.
- One harder session in zones 4 and 5. Intervals or guided HIIT, with full rests between efforts.
- Recovery days in zone 1, or rest. Keep them easy so the hard day stays hard.
Give each session its zone when you plan it, not when you start it. A workout planner app that puts runs, lifts and rest in the same week makes it easy to see where the hard days fall.
Training by zone with Kinetic on Apple Watch
Kinetic builds your five zones with the reserve method above: Tanaka for your maximum and your resting heart rate from Health, which you can change in Settings at any time. Pick your target zone in Settings, or on the watch before you start a standard, HIIT or custom workout. The watch then shows live heart rate and your zone, taps your wrist and speaks up the moment you leave the target zone, and runs without your iPhone, even offline. Afterwards you see time in each zone and in your target zone. You can plan the week's runs with a zone for each, and live heart-rate zones are free, with no account.
Questions
Why don't I see heart rate zones on my Apple Watch?
Apple only calculates zones once your date of birth is in the Health app on your iPhone, and the zone view appears in cardio-focused workouts such as an outdoor run. Add your date of birth, start a cardio workout and turn the Digital Crown to the Heart Rate Zone view.
Can I set my own heart rate zones on Apple Watch?
Yes. In the watch's Settings app, go to Workout, then Heart Rate Zones, tap Manual, and enter the lower and upper limits for zones 2, 3 and 4. The Apple Watch app on iPhone has the same setting under My Watch.
What is zone 2 on Apple Watch?
Zone 2 is the second of five zones: an easy effort where you can still talk in full sentences. With the reserve method it starts at 60% of your heart-rate reserve above your resting rate; for the 35-year-old above, that is about 134 to 147 beats per minute.
Which is better, 220 minus age or 208 minus 0.7 times age?
Tanaka's study of healthy adults found 208 minus 0.7 times age predicts maximum heart rate better, and that 220 minus age underestimates it in older adults. Both are averages, so your own maximum can differ.
Sources
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