The five zones
- Zone 1 (50–60%) — warm-up and recovery.
- Zone 2 (60–70%) — easy endurance, burns a high share of fat.
- Zone 3 (70–80%) — aerobic fitness.
- Zone 4 (80–90%) — threshold, race pace.
- Zone 5 (90–100%) — short maximum intervals.
Measure your resting heart rate in bed after waking for the most accurate Karvonen zones.
Frequently asked questions
Which formula is better?
Tanaka is more accurate for adults over 40; 220 − age is the classic rule.
Can I enter my real max?
Yes, a measured maximum from a test gives the best zones.
Is it medical advice?
No — consult a doctor before intense training if you have health concerns.