Five zones, one effort at a time.
Use your age and resting heart rate to see the bpm ranges behind easy aerobic work, steady sessions and the short, hard efforts that should stay short.
Find the right effort.
- Z1 · RecoveryEasy, conversational50–60%120–132
- Z2 · Aerobic baseComfortable, sustainable60–70%132–144
- Z3 · SteadyBreathing harder70–80%144–156
- Z4 · ThresholdShort sentences80–90%156–168
- Z5 · HardHard efforts only90–100%168–180
Most easy training should sit in Z1–Z2. Save Z4–Z5 for short, deliberate efforts — and use the talk test when a wrist reading looks wrong.
Estimates only. Maximum heart rate is an age-based average, not a measurement. If you take medication that affects heart rate or have a cardiac condition, ask your doctor before training to these zones.
A compass, not a speedometer.
Maximum heart rate is estimated as 208 minus 0.7 times your age. The Karvonen method then places each zone between your resting heart rate and that estimate, which makes the result more personal than a percentage of max alone.
Wrist monitors lag behind short efforts and can be thrown off by cold hands or a loose strap. The talk test is still a good second opinion: easy work should allow full sentences, threshold work should not.
- Max HR
- 208 − 0.7 × age, rounded to the nearest beat.
- Zone formula
- Resting HR + (max HR − resting HR) × the zone percentage. Zones run from 50–60% through 90–100%.
- Resting HR
- Use a quiet morning reading if you have one. The default of 60 bpm is a placeholder, not your measurement.
- Before you train
- Medication, illness and cardiac conditions change the picture. Ask a doctor before training to zones that are new to you.
Easy days should feel easy.
If every session sits in the middle, a coach can help you build the contrast that makes training work.