Heart rate zone calculator
Two numbers from your watch give five zones that fit your heart, not an average one. Zone 2, the easy aerobic base, is the one most people get wrong.
The formula
Each boundary is resting heart rate plus a percentage of heart-rate reserve, which is maximum minus resting. Zone 1 is under 60% of reserve, zone 2 is 60 to 75%, zone 3 is 75 to 87%, zone 4 is 87 to 95%, and zone 5 is above 95%.
Without a measured maximum the calculator predicts one with 208 − 0.7 × age, which fits pooled data better than 220 − age. A maximum measured on a hard hill effort with a chest strap is better than either.
Check it with the talk test
In zone 2 you can speak in full sentences. In zone 3, short phrases. In zone 4, a word or two. If the calculated zone 2 does not match, your maximum is probably off; fix the maximum, not the formula.
PeakBeat does this from your own data, every day. Your effort writes the setlist. Join the free beta →
Questions
Why not just use percent of maximum?
How often should I recalculate?
Which zone burns the most fat?
Sources
- Karvonen M.J., Kentala E., Mustala O. (1957). The effects of training on heart rate: a longitudinal study. Ann Med Exp Biol Fenn. https://pubmed.ncbi.nlm.nih.gov/13470504/
- Tanaka H., Monahan K.D., Seals D.R. (2001). Age-predicted maximal heart rate revisited. J Am Coll Cardiol. https://www.jacc.org/doi/10.1016/S0735-1097(00)01054-8