Five training zones from your age, with an option for the more accurate reserve method.
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Measured lying down before getting up. Switches to the more accurate reserve method.
Max heart rate formula
Both formulas are estimates with about ten beats of variation either way. Only a proper test gives your real maximum.
Estimated maximum heart rate
184 bpm
Add a resting rate for more accurate zones
Zone 1Recovery
Very easy. Warm-ups and active recovery.
Zone 2Endurance
Conversational. Where most endurance is built.
Zone 3Tempo
Comfortably hard. Easy to spend too much time here.
Zone 4Threshold
Hard. Sustainable for around an hour at best.
Zone 5Maximum
All out. Short intervals only.
It is the one everybody knows and it carries a standard deviation of about ten to twelve beats per minute. For a 40 year old, that means a real maximum anywhere between roughly 168 and 192.
The Tanaka formula, 208 minus 0.7 times age, fits observed data better across adults and is offered here as an alternative. Neither replaces an actual measured maximum, which needs a proper test and is genuinely unpleasant.
The Karvonen method works from heart rate reserve, the gap between resting and maximum, rather than from maximum alone. Because resting rate reflects your actual fitness, zones built this way sit closer to how the effort feels.
It matters most at the low end. Zone 2 calculated from maximum alone often comes out too low for a trained person, which is why people report having to walk to stay in it.
Zone 2 is the one worth understanding. It is conversational effort, sustainable for hours, and it is where most endurance adaptation is built. It also feels too easy, which is why people skip it and spend every session in zone 3.
The fat burning label attached to the lower zones is technically true and practically misleading. A higher share of energy comes from fat at low intensity, but the total burned is smaller. For fat loss, total calories and the diet decide it.
This sets the estimated maximum heart rate before anything else is derived.
Measured first thing in the morning before getting up. This switches the calculation to the more accurate reserve method.
Tanaka fits observed data slightly better than the familiar 220 minus age.
It will feel too easy. That is the point, and it is where most endurance adaptation happens.
Give it any two of pace, time, and distance, and it works out the third.
Set work and rest, choose your rounds, and go. Includes a Tabata preset.
Estimates how many calories you burn in a day, and what to eat to hold, lose, or gain weight.
A calculator tells you where you are once. If the thing you actually want is to keep something up, that takes a record rather than a result.
