Last updated 23 August 2026
How the zones are set
Maximum heart rate is estimated as 220 minus your age, then each zone is a percentage band of that maximum. Zone 1 (50-60%) is a light warm-up pace; Zone 3 (70-80%) is a solid aerobic effort most people can sustain for a while; Zone 5 (90-100%) is near-maximum, sustainable only briefly.
The 220-minus-age formula is a population average, not a personal measurement — actual maximum heart rate can differ by 10-15 beats either way. It's a reasonable starting point for structuring training, not a precise medical figure.
Method, limitations and sources
Formula. Maximum heart rate is estimated as 220 minus your age, and the five zones are fixed percentages of that maximum: 50–60%, 60–70%, 70–80%, 80–90% and 90–100%.
Inputs it needs. Your age. Nothing else.
Age-based maximum heart rate is a population estimate, not your number. The 220-minus-age rule describes an average across a large group. Individual maximum heart rates scatter widely around it — commonly by 10 to 12 beats per minute in either direction, and sometimes more. Two people the same age can have genuinely different maximums, and neither is abnormal. The only reliable way to know yours is a supervised maximal exercise test.
What it assumes. A healthy adult not taking medication that affects heart rate. Beta blockers and several other drugs lower both maximum and working heart rate, which makes percentage zones meaningless without medical input.
Where it is least reliable. Older adults and well-trained athletes, for whom the formula tends to drift; anyone with a heart condition, arrhythmia or pacemaker; and anyone new to exercise.
When not to use it. Do not use these zones to push through chest pain, dizziness or unusual breathlessness, and do not use them at all if you have a heart condition or take medication affecting your heart rate without asking your doctor first. Perceived effort — whether you can still hold a conversation — is a sound cross-check on any zone number.
- American Heart Association — Target Heart Rates Chart, which sets out the moderate (50–70%) and vigorous (70–85%) ranges and notes that medication can change your target zone.
Common questions
How is maximum heart rate estimated?
Using the standard 220 minus age formula. It's a population average, not a measurement of you specifically — individual max heart rate can vary by 10-15 beats from the formula's estimate, more precisely measured through a supervised fitness test.
Which zone should I train in?
It depends on the goal. Zone 2 (light) builds aerobic base and is where most easy training happens. Zone 3-4 improves cardiovascular fitness faster but is more fatiguing. Zone 5 is for short, intense efforts, not sustained training.
Is this safe to use for intense exercise?
These are general estimates, not a substitute for medical clearance. If you have a heart condition or are new to intense exercise, check with a doctor before training in the higher zones.