Set Training Zones That Match Your Actual Effort
How heart rate zones are estimated, why the age formula is approximate, and how to sanity-check them.
Training zones exist to stop easy sessions drifting hard and to keep hard sessions genuinely hard. They are built from an estimated maximum heart rate, and that estimate is where most of the error lives.
The age formula is an average
Subtracting age from 220 produces a population average with a spread of roughly ten to twelve beats either side. For an individual, that is enough to shift an entire zone boundary.
Cross-check with perceived effort
An easy zone should allow full sentences. A threshold effort should permit only short phrases. If the numbers and the feeling disagree consistently, trust the feeling and adjust the zones.
Get clearance where it matters
Maximal testing and high-intensity training carry real risk for people with cardiac conditions or a long break from exercise. Speak to a clinician before setting zones from a maximal effort.