Maximum heart rate (HRmax)

What it is

Maximum heart rate (HRmax) is the highest number of beats per minute your heart reaches at maximal effort. It falls with age, and in a large 2001 analysis it was predicted mostly by age alone, regardless of how active people were.

Why it matters for training decisions

Many heart rate zone systems are built as percentages of your max (or of your heart rate reserve, which also uses it). If your max is wrong, every zone is wrong. That can mean your “easy” runs are really moderate, or your threshold intervals are too soft.

Estimates and their limits

The old 220 minus age formula was never properly validated. In 2001, Tanaka and colleagues pooled data from 351 studies and proposed 208 − 0.7 × age for healthy adults, finding that 220 minus age underestimates max heart rate in older adults.

Any formula is a population average, though. Individuals can sit well above or below it. A tested max from a hard race finish or a structured field test is usually more accurate. Only do maximal efforts if you’re healthy, and get medical advice first if you have a heart condition or symptoms.

How P247 uses it

P247’s heart rate zones are off until you turn them on. When you do, you choose the maximum heart rate they’re built from: a number you enter yourself, the highest heart rate you held for 60 seconds in your Apple Health workouts over the last 365 days (if you accept it), or the Tanaka age estimate (208 − 0.7 × age). The workout value is an estimate from your own data, not a tested max.

This glossary is general information to help you understand your training data. It isn't medical advice, diagnosis or treatment. For injury, illness, medication, blood test results or any health concern, speak to a qualified health professional.

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