Heart rate training zones are a foundational concept for endurance athletes — especially runners — looking to train smarter, not just harder. But not all heart rate zones methods are equal, and not all training philosophies define them in the same way.
So, what exactly is a heart rate zone? And which method should you follow?
Let’s break it down.
What Are Heart Rate Training Zones?
Heart rate zones are defined ranges of heart rate (measured in beats per minute or % of heart rate) that correspond to different intensities of effort. Each zone targets a specific physiological response — such as improving fat metabolism, increasing lactate threshold, or enhancing VO₂ max.
Think of them as “effort categories” for your workouts:
- Zone 1 = very easy recovery
- Zone 2 = aerobic base building
- Zone 3 = tempo/grey zone
- Zone 4 = threshold work
- Zone 5+ = high-intensity intervals
But here’s the catch: different training systems define these zones differently — and calculate them based on different data points.
How Are Heart Rate Zones Calculated?
There are four main ways zones are determined:
1. Maximum Heart Rate (MHR)
Based on your tested maximum heart rate.
(It is common to use the formula 220 – age, to calculate your max heart rate, however it is advisable NOT to do so.
Zones are then shown as percentages of your max (e.g. Zone 2 = 60–70% MHR).
Pros: Simple.
Cons: Generic and often inaccurate unless tested in a lab or field session.
2. Lactate Threshold (LT or LTHR)
This method sets your zones relative to your threshold — the effort just below where lactic acid accumulates rapidly.
Pros: Highly accurate and individualised. Best for serious endurance athletes.
Cons: Requires a test (either lab-based or field-based) to determine LTHR.
3. Max & Resting Heart Rate (Karvonen Formula)
Takes your resting heart rate into account, creating more personalised zones.
Formula:
Training HR = ((HRmax − HRrest) × %Intensity) + HRrest
Pros: More tailored to your fitness level.
Cons: Requires consistent measurement of your resting HR.
4. Hybrid Methods (LT + Max HR)
Combines Lactate Threshold and Max HR to refine zones further.
Pros: Blends performance insights with intensity.
Cons: More complex to calculate and manage.
Zone Systems Are Not All the Same!
TrainingPeaks lists over a dozen zone systems used by different coaches and organisations:
Each system has a slightly different interpretation:
- Joe Friel (7 zones) – Popular among triathletes and serious age-groupers. Based on LTHR.
- 80/20 Running (7 zones) – Based on polarized training: 80% easy (Z1–Z2), 20% hard (Z4–Z5).
- Coggan/USAC (5 zones) – More common in cycling but adapted for runners.
- CTS & Durata (6–10 zones) – Very detailed; great for elite athletes and coaches.
So Which One Should You Use?
It depends on your goals, experience, and the tools you have:
- Beginner or casual runner? Use MaxHR-based zones to get started.
- Intermediate or focused on a goal race? Do a field test to estimate your LTHR and use Friel or 80/20 methods.
- Data nerd or coached athlete? Consider combining LT and Max HR with a detailed system like CTS or Durata.
In Summary
Not all heart rate training zones are the same. They vary based on how they’re calculated and which coaching philosophy you follow. Understanding this difference — and choosing a method that suits you — is key to unlocking smarter, more effective training.
Want help determining your correct zones and building a plan that works for you?
Visit A-Team Coaching or reach out — we’ll guide you every step of the way.