Heart Rate Zones Explained
Train smarter by understanding the five zones and what each does.
The five zones
Zones are bands of your maximum heart rate. Zone 1 is a gentle warm-up, zone 2 builds aerobic base, zone 3 is steady cardio, zone 4 pushes threshold and zone 5 is all-out effort.
How to calculate
The Karvonen method uses heart rate reserve, which is maximum minus resting heart rate. It personalises zones better than percentages of maximum alone.
How to use zones
Spend most weekly cardio time in zones 2 and 3, with a little high-intensity work. Use the talk test as a cross-check: you should speak in sentences in zone 2.
Try it: Target Heart Rate Calculator
Example with sample values. Open the full calculator →
Most health benefit comes from zones 2–3. Estimates can vary by 10 bpm either way between individuals.
Educational content only. This article does not replace advice from a qualified health professional. Medical disclaimer.