Lactate threshold: what it is and how to estimate it
What lactate threshold is, why it is the key reference for your zones and how to estimate it without a lab.
Lactate threshold is the intensity above which lactate starts to build up in the blood faster than the body can clear it. Above it, fatigue comes quickly; below it, you can keep going for a long time.
Why it matters so much
It's the reference your training zones and load are built on. And in long events, the pace you can sustain depends mostly on how high your threshold is.
How to estimate it without a lab
- 30-minute running test: average heart rate over the last 20 minutes approximates your threshold heart rate, and average pace your threshold pace.
- 20-minute bike test: 95% of average power is a good approximation of FTP.
- A recent race: the pace of a race lasting about 50-60 minutes is very close to threshold.
- Your own workouts: your best sustained effort of about 20 minutes in recent months.
Review it often
Threshold changes with training. Traincontrol estimates it from your recent activities and tells you which session each value comes from, although what you type in manually always wins.