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Heart rate zones
HRmax ≈ 184 (Tanaka) · Fox 185 · Gulati 175
Zone 1 · Recovery
92–110
50–60%
Zone 2 · Easy / aerobic
110–129
60–70%
Zone 3 · Moderate (tempo)
129–147
70–80%
Zone 4 · Threshold
147–166
80–90%
Zone 5 · VO2max / anaerobic
166–184
90–100%
How to use it
Enter your age to get 5 zones via the Tanaka formula. If you know your resting heart rate (measure it lying down in the morning before getting up), the calculation gets more accurate via the Karvonen heart-rate-reserve method. If you have a lab-tested max HR, enter it — it always beats any age-based formula.
Formula and source
HRmax (Tanaka) = 208 − 0.7 × age
Without resting HR: zone = HRmax × %
With resting HR (Karvonen): zone = (HRmax − HRrest) × % + HRrest
Tanaka, Monahan, Seals, 2001 (J Am Coll Cardiol) · Karvonen et al., 1957
Worked example
Age 35 → HRmax ≈ 184. Zone 2 (easy, 60–70%) without resting HR: 110–129 bpm. With a resting HR of 55, Karvonen gives 132–145 bpm — higher, because the method uses your personal reserve, not just the max.
Limitations
- Tanaka is a population-average estimate; spread between people of the same age can reach ±10–15 bpm.
- A lab VO2max test or a field max-HR test beats any formula; treat this as a starting point, not gospel.
- Heart rate shifts with heat, dehydration, caffeine, stress — real-time zones can drift 5–10 bpm from the chart.