Lactate threshold heart rate is the highest heart rate you can hold for about an hour. Basing zones on it, rather than on a maximum heart rate formula, makes them much more personal.
How to use the Cycling Heart Rate Zones Calculator
- I know
- Lactate threshold heart rate (bpm)
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Enter your LTHR, or the average heart rate over the last 20 minutes of a solo 30-minute time trial.
Inputs explained
| Field | What to enter |
|---|---|
| I know | Choose one: My LTHR, My 30-min time-trial average (last 20 min) |
| Lactate threshold heart rate (bpm) | A number |
What each result means
- Zone 1 – Recovery: below = round(0.81×[LTHR used])
- Zone 2 – Aerobic: from = round(0.81×[LTHR used])
- Zone 2 – up to = round(0.89×[LTHR used])
- Zone 3 – Tempo: from = round(0.90×[LTHR used])
- Zone 3 – up to = round(0.93×[LTHR used])
- Zone 4 – Sub-threshold: from = round(0.94×[LTHR used])
- Zone 4 – up to = round(0.99×[LTHR used])
- Zone 5a – Super-threshold: from = round(1.00×[LTHR used])
- Zone 5a – up to = round(1.02×[LTHR used])
- Zone 5b – Aerobic capacity: from = round(1.03×[LTHR used])
- Zone 5b – up to = round(1.06×[LTHR used])
- Zone 5c – Anaerobic capacity: above = round(1.06×[LTHR used])
Example values
How the main result changes when Lactate threshold heart rate changes and everything else stays at the example values above:
| Lactate threshold heart rate (bpm) | Zone 4 – Sub-threshold: from (bpm) |
|---|---|
| 82.5 | 78 |
| 123.75 | 116 |
| 165 | 155 |
| 206.25 | 194 |
Formula
Zones as % of LTHR: Z1 < 81% · Z2 81–89% · Z3 90–93% · Z4 94–99% · Z5a 100–102% · Z5b 103–106% · Z5c > 106%
Worked example
Inputs — I know: My LTHR; Lactate threshold heart rate (bpm): 165.
Results — LTHR used = 165 bpm; Zone 1 – Recovery: below = 134 bpm; Zone 2 – Aerobic: from = 134 bpm; Zone 2 – up to = 147 bpm; Zone 3 – Tempo: from = 149 bpm; Zone 3 – up to = 153 bpm; Zone 4 – Sub-threshold: from = 155 bpm; Zone 4 – up to = 163 bpm; Zone 5a – Super-threshold: from = 165 bpm; Zone 5a – up to = 168 bpm; Zone 5b – Aerobic capacity: from = 170 bpm; Zone 5b – up to = 175 bpm; Zone 5c – Anaerobic capacity: above = 175 bpm.
Key terms
- LTHR
- Lactate threshold heart rate.
Frequently asked questions
How do I find my LTHR?
Ride a solo 30-minute time trial; your average heart rate for the last 20 minutes ≈ LTHR.
Is cycling LTHR the same as running?
No – it is usually 5–10 bpm lower on the bike.
Where should most training be?
Zones 1–2 for most of your volume.
Why use heart rate instead of power?
Heart rate is cheaper to measure; power responds faster.