Glossary
Heart Rate Zones
Updated August 16, 2025
Heart Rate Zones group intensity to guide cardio training.
Typical zones
| Zone | % max HR | Feel and purpose |
|---|---|---|
| Z1 | 50%–60% | Easy, recovery, base building |
| Z2 | 60%–70% | Comfortable, aerobic endurance |
| Z3 | 70%–80% | Moderate, tempo |
| Z4 | 80%–90% | Hard, threshold |
| Z5 | 90%–100% | Very hard, short efforts |
Device‑specific definitions may vary slightly.