How the zones are calculated
Five zones with boundaries at 60, 70, 80 and 90% of your maximum heart rate. These are the same zones Kiiro uses by default, with the same names: Easy, Base, Tempo, Threshold and Max.
How do I find my maximum heart rate?
The estimate of 220 minus your age is a starting point. A better number is the highest heart rate you have seen at the end of a hard race or an all-out hill session, when you were fresh and the reading looked steady rather than spiky. If your easy runs feel easy but land in zone 3, your maximum is probably set too low.
Which method should I use?
| Method | You need | Good when |
|---|---|---|
| Maximum heart rate | Your maximum, or your age | You want a quick start. This is what Kiiro uses by default. |
| Heart rate reserve | Maximum and resting heart rate | Your resting heart rate is unusually low or high, so percentages of maximum fit you badly. |
| Lactate threshold | A 30-minute test run | You train seriously and want zones anchored to what you can actually sustain. |
The methods give different numbers for the same person. Pick one and stay with it; do not compare a zone 2 from one method with a zone 2 from another.
Using your zones
- To use them on your watch, see how Apple Watch sets heart rate zones and how to change them.
- For what zone 2 is and why it matters, see Zone 2.
- Kiiro shows your time in zones for every workout and how your weeks split between low, medium and high intensity. See heart rate zones in Kiiro.
