Pace tells you how fast you are running. Heart rate tells you what that pace costs. That second signal helps separate training that builds fitness from training that merely accumulates fatigue. Heart rate training is not just for professionals — it helps you stop running everything at one pace and give every session a clear purpose.
Why heart rate, not pace alone?
A 5:30/km pace can feel easy on Monday and hard on Thursday because of heat, hills, poor sleep or fatigue from an earlier session.
Pace is an external number. Heart rate gives you a better picture of how demanding the effort is for your body. An easy run guided by heart rate can therefore remain easy in the heat, uphill or after a demanding week.
The key values: maximum heart rate, resting heart rate and LTHR
Maximum heart rate (HRmax)
The highest heart rate you reach at maximum effort. The formula 208 − 0.7 × age is an indicative age-based estimate, and individual variation can be substantial. A reliably measured personal value is more useful for personal zones.
Resting heart rate (RHR)
Your morning heart rate at rest. The Karvonen method combines it with HRmax to calculate heart rate reserve. Resting heart rate is a useful supporting signal when read against your own history, not a training verdict on its own.
LTHR — lactate threshold heart rate
Your heart rate around an effort you could race for roughly an hour. An indicative field test is 30 minutes at a steady hard effort, using the average from the final 20 minutes. Find the detailed zone calculation in the heart rate zone calculator.
Five zones and what they are for
Indicative ranges as a percentage of maximum heart rate:
| Zone | % HRmax | Feel | Purpose |
|---|---|---|---|
| Z1 Recovery | 50–60% | very easy, almost walking | active recovery |
| Z2 Aerobic base | 60–70% | full-sentence conversation | foundational volume |
| Z3 Aerobic tempo | 70–80% | comfortably quick, shorter sentences | controlled steady running |
| Z4 Threshold | 80–90% | comfortably hard, a few words | tempo / threshold work |
| Z5 Maximum | 90–100% | all-out, no talking | short intervals |
Zone 2: the foundation of most endurance training
Most of your runs should feel easy — and many recreational runners make them unnecessarily hard. Z2 builds the aerobic foundation that supports faster workouts and races. A practical check is the ability to speak in full sentences. If that means slowing down, that is completely fine.
Z3 has a place as controlled aerobic tempo. But when most runs land at a moderately hard effort, fatigue can accumulate and quality sessions can lose their quality.
What a week by zones can look like
For a runner training three or four times a week, the structure may look like this:
- 2–3 easy Z2 runs — the foundation of your volume, including a longer run that can sit at the lower end of Z2.
- 1 quality session — a Z3–Z4 tempo run or, for more advanced runners, intervals reaching Z4–Z5. With three or four weekly runs, one quality session is enough for most recreational runners.
- Z1 for warm-ups, cool-downs and recovery — very easy movement after harder days.
A simple guideline often used is roughly 80% of training time at an easy intensity and 20% at a harder intensity. It is not a compulsory mathematical quota for every week; the longer-term balance and purpose of each session matter more.
We cover training load in a separate guide. Training load.
Common heart rate training mistakes
- Everything in Z3. Easy runs become too demanding while quality sessions lack enough intensity for their purpose, potentially creating plenty of fatigue without a clear training stimulus.
- Panicking about a higher heart rate in the heat. Heart rate can rise at the same pace in hot conditions. Slow down and follow the planned intensity instead of forcing the pace.
- Comparing zones with a friend. Heart rate is highly individual. Compare your values with your own zones and history.
- Zones calculated from the wrong anchor. An age-based HRmax estimate can be well off for an individual. If the zones consistently disagree with perceived effort, verify the anchor — for example with an LTHR test.
- Obeying every single beat. Heart rate is a tool, not a dictator. Brief changes on hills, in wind or at the start are normal; focus on the overall pattern and trend.
Measurement limits: wrist sensor vs chest strap
An optical wrist sensor is often sufficient for ordinary easy runs, but it can lag or misread during rapid intensity changes. One possible error is cadence lock, when a device mistakes step cadence for heart rate.
A chest strap is usually more accurate during rapid changes and is useful for an LTHR test or intervals. It is not essential for everyone — wrist-based measurement may be entirely adequate for regular easy running.