Zones that agree with your watch.
Enter your maximum and resting heart rates and get your five zones.
Most zone calculators use a percentage of maximum alone, which reads eight to ten beats hot for anyone with a low resting heart rate — so genuinely easy running lands in tempo and easy days stop being easy.
Calculated from heart-rate reserve — the range between resting and maximum — which is what your watch uses. A percentage-of-maximum calculator would put zone 2 at 114–132, which is why easy running so often lands in tempo.
How it works
Heart-rate reserve, also called the Karvonen method: the zones are set as a percentage of the range between your resting and maximum heart rates, not of your maximum alone. Bands sit at 60, 70, 80 and 90 per cent of that reserve — the same edges Garmin uses by default, which is what makes the numbers match your watch. If you do not know your resting rate we fall back to percentage of maximum.
Max 190, resting 48. Zone 2 runs 133–146 rather than the 114–132 a percentage-of-max calculator gives you. Nineteen beats of difference, and it is why your easy runs have felt hard.
Questions
Why do my zones differ from another calculator?
Most use a percentage of maximum heart rate alone. This uses heart-rate reserve, the range between resting and maximum, which is what Garmin and most watches use.
How do I find my maximum heart rate?
The highest figure you have actually seen in a hard race or session beats any age-based formula. Structur detects it from your training automatically.
Should I train by heart rate or pace?
Pace for shorter, faster work; heart rate for easy running and in heat or on hills. Structur lets a coach prescribe either.
This number is where Structur starts.
Coaches prescribe against it. Self-coached runners build a block around it. Either way it stays current on its own.