The five zones
Maximum heart rate is estimated from age; the zones are bands of it. With a resting heart rate the Karvonen formula is used instead — target = resting + (max − resting) × % — which shifts the zones up for fitter people.
| Zone | % of max | Feels like |
|---|---|---|
| 1 Very light | 50–60% | Easy chat, warm-up |
| 2 Light | 60–70% | Comfortable, can talk in sentences |
| 3 Moderate | 70–80% | Breathing harder, short sentences |
| 4 Hard | 80–90% | A few words at a time |
| 5 Maximum | 90–100% | Cannot talk, seconds to a minute |
Common questions
What's the Karvonen method and why does resting heart rate matter?
Karvonen calculates zones from your heart rate reserve (max minus resting) instead of max alone — target = resting + (max − resting) × %. Two people with the same max but different fitness levels (and so different resting rates) get meaningfully different zones this way, which plain age-based zones miss.
Which max-HR formula should I use?
220 − age is the classic, simplest one but tends to be less accurate at the extremes of age. Tanaka (208 − 0.7 × age) is generally considered more accurate across a wider age range; Gulati is specifically calibrated for women.
For general information only — not medical advice. Talk to a doctor about anything that concerns you.