When people talk about heart rate training, you'll hear "Zone 2" and "Zones 1-5". But what are these zones, and how do you find them?
In short: zones 1-5 are intensity levels
Based on percentage of max heart rate, training intensity is split into 5 zones:
| Zone | Intensity (% max HR) | Feeling | Use |
|---|---|---|---|
| Zone 1 | 50-60% | Very easy, like walking | Recovery, warm-up |
| Zone 2 | 60-70% | Can talk, slightly breathless | Aerobic base, fat burn |
| Zone 3 | 70-80% | Clearly breathless, hard to talk | Endurance, tempo |
| Zone 4 | 80-90% | Very breathless, single words only | Lactate threshold, speed |
| Zone 5 | 90-100% | Explosive, can't talk | VO₂ max, sprint |
How to find your zone?
Use your "max heart rate". Rough formula: 220 − age. E.g. at 30, max HR ≈ 190, so Zone 2 is 60-70% = 114-133 bpm.
Simplest: the "talk test" — if you can still speak short sentences (but not sing), you're in Zone 2.
Why is Zone 2 so important?
- Builds the aerobic engine: increases mitochondrial density and fat-burning ability.
- Recovers fast: can be done daily without overtraining.
- Seiler (2010): elite endurance athletes spend about 80% of training in Zone 2.
Conclusion: Zone 2 is the foundation; the other zones are advanced. Build lasting endurance starting from Zone 2.
Summary and recommendations
- Calculate your max HR: 220 − age.
- Find Zone 2: 60-70%, or a "talkable" pace.
- 2-3 times a week: 45-60 minutes each.
- Don't rush: the most common Zone 2 mistake is going too fast.
In one sentence: heart rate zones 1-5 are intensity levels from easy to hard — Zone 2 is the aerobic foundation, and slow enough to talk is correct. Slow is fast.