Calculate heart-rate training zones
Heart-rate zones provide a simple way to organise aerobic training intensity. ATHLOMETRY supports two common approaches: percentages of maximum heart rate and the Karvonen method, which also accounts for resting heart rate.
% HRmaxSimple percentage method
KarvonenUses heart-rate reserve
5 zonesPractical training ranges
Karvonen formula
Target HR = (HRmax − resting HR) × intensity + resting HR
Heart-rate reserve is the difference between maximum and resting heart rate. Because resting heart rate varies between people, the Karvonen method can produce different training ranges even when two athletes share the same HRmax.
Measured HRmax is better than an age estimate
If you know your maximum heart rate from a valid maximal test, enter it directly. Otherwise, ATHLOMETRY currently estimates it using 208 − 0.7 × age, an equation derived from a large meta-analysis and laboratory cross-validation in healthy adults.
Age equations describe population averages and can be meaningfully wrong for a specific person. Treat estimated zones as starting points rather than exact physiological thresholds.
How to interpret the five zones
The five-zone boundaries in this calculator are practical percentage bands. They are useful for organising sessions, but they should not be confused with directly measured lactate or ventilatory thresholds. Different coaching systems may use different zone definitions.
Should I use %HRmax or Karvonen?
Both can be useful. %HRmax is simpler; Karvonen includes resting heart rate and therefore individualises the calculation slightly more.
Is 220 minus age used here?
No. When HRmax is unknown, ATHLOMETRY uses 208 − 0.7 × age.
Why is my watch showing different zones?
Watches and training platforms can use different HRmax values, threshold estimates and zone systems. Check the method and HRmax stored in your device before comparing ranges.
Can zones change over time?
Yes. Resting heart rate, measured HRmax, fitness and threshold values can change, and devices may also update their estimates.