Target Heart Rate Zones: Train Smarter, Not Just Harder
Heart rate zones turn 'exercise harder' into a precise plan. Train in the right zone and you target the adaptation you actually want.
Learn to estimate your maximum heart rate and the five training zones.
The formula
A common estimate is max HR ≈ 220 − age. Zones are percentages of that maximum.
What each zone does
Zones 1–2 build aerobic base and burn fat; zone 3 improves endurance; zones 4–5 sharpen speed and VO₂ max.
Use a chest strap
For accurate zone training, a chest-strap monitor beats wrist optical sensors during intense efforts.
Related calculators
Frequently asked questions
Is 220 − age accurate?
It's a useful estimate but varies by individual; a lab or field test is more precise.
Which zone burns most fat?
Lower zones use a higher fat fraction, but higher zones burn more total calories.
This tool provides educational information and is not intended to replace professional medical advice.