ΔέσεThe 5 Heart-Rate Zones, explained simply
If you wear a sports watch, you've probably seen workouts full of "Zone 2", "Zone 4", or "150 bpm". For many runners those are just numbers. In reality, though, heart-rate zones are one of the most useful guides for training the right way.
What heart-rate zones are
Heart-rate zones split your training into 5 intensity levels, based on a percentage (%) of your maximum heart rate. Each zone corresponds to a different intensity level and triggers different adaptations in your body — some help recovery, some build endurance, others build speed. Knowing which zone you're in helps you stop running at the same pace every time, with no clear purpose.
Max heart rate208 − 0.7 × age
% range or KarvonenMore accurate with resting HR
5 Training ZonesFrom recovery to maximum intensity
What each one does
| Zone | % Max Heart Rate | How it feels | When to use it |
|---|---|---|---|
| Z1 · Recovery | 50-60% | Very easy, comfortable talking | Warm-up, cool-down, active rest |
| Z2 · Aerobic base | 60-70% | Comfortable, can hold a conversation | Most of your runs — builds endurance |
| Z3 · Tempo | 70-80% | Moderately hard, a bit breathless | Improves aerobic fitness & race pace |
| Z4 · Threshold | 80-90% | Hard, only a few words at a time | Raises your "speed endurance", lactate threshold |
| Z5 · Maximum | 90-100% | Very intense, only for a short time | Sprints / VO₂max intervals, speed |
💡 For a more accurate result: If you know your resting heart rate
(measured in the morning, before getting out of bed), use the Karvonen
method instead of a plain percentage of your max heart rate — it accounts for your own
fitness level. Zones can vary slightly depending on your watch or the calculation method
it uses.
💙 Want your own zones?
Use our free Heart-Rate Zones Calculator.
Use our free Heart-Rate Zones Calculator.
What it looks like in practice
Zones aren't theory — this is how they show up in a real training week:
Easy Run
⏱ 35 min
❤️ ~135 bpm
Zone 2
Tempo
⏱ 20 min
❤️ ~168 bpm
Zone 4
Intervals
⏱ 5 × 800m
❤️ 178+ bpm
Zone 5
How much time in each zone
Ever finished an "easy" run feeling completely wrecked? You probably spent that time in Zone 3 or 4 when the goal was Zone 2 — without noticing, you "stole" intensity from a day that was supposed to be relaxed.
You don't need to split your time equally across the 5 zones. Most runners — even elite ones — spend most of their training at low intensity, keeping a small, targeted amount of time for the hard stuff. It's the same idea behind polarized 80/20 training.
👉 Read also: Why elite runners run slow on easy days.
Zones 4-5Hard · ~10% of training time
Zone 3Tempo · ~10-15%
Zones 1-2Base · ~75-80% of training time
❌ Myth: The harder I run every time, the faster I'll improve.
✅ Truth: Without enough time in low zones you don't build endurance, and hard sessions lose quality due to accumulated fatigue.
Heart-rate zones aren't there to hold you back. They're there to show you when to slow down and when it's actually worth pushing. When every session has the right purpose, progress comes more steadily — with fewer injuries.
You don't need to chase perfect numbers. It's enough to know the goal of each session — and heart-rate zones are a simple way to hit that goal more often. 🏃♀️
Frequently asked questions about heart-rate zones
Should I always run in Zone 2?
No. Most of your training is best done in the low zones, but the higher zones have their role in small, targeted doses — each zone serves a different purpose.
Why is my heart rate high even though I'm running slowly?
Very common in beginners: your aerobic base is still being built. Heat, fatigue, poor sleep, caffeine and stress also push heart rate up. If you can talk comfortably, don't panic over one day's number — look at the trend across weeks.
How accurate is my watch's heart-rate reading?
Wrist optical sensors are fairly reliable at a steady pace, but they can lag behind during sharp changes in intensity, such as intervals. If you want more accuracy, a chest strap remains the most reliable option.
My watch shows different zones than the table — which one is right?
Calculation methods differ: a simple percentage of maximum heart rate, Karvonen, or each manufacturer's own algorithm. Small differences are normal — what matters is using the same method consistently, so you can compare your runs properly.
Do I really need a watch to train by zones?
No. Perceived effort and how comfortably you can talk — the "how it feels" column of the table — guide you quite well. A watch simply makes the same information more measurable.
3 things to remember
- Every zone has a different purpose — not all of them are about speed.
- 75-80% of your training should be in Zone 1-2.
- Find your own zones with the heart-rate calculator.
Sources
The main scientific references behind this article:
- Tanaka, H., Monahan, K. D., & Seals, D. R. (2001). Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology, 37(1), 153–156. JACC →
- Karvonen, M. J., Kentala, E., & Mustala, O. (1957). The effects of training on heart rate: a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniae, 35(3), 307–315. PubMed →
- Daniels, J. (2021). Daniels' Running Formula (4th ed.). Human Kinetics. Human Kinetics →
