The lactate threshold is one of the most commonly used references for fixing intensities in endurance sports. But it's not a single number: there are several threshold concepts and it's good to know which one you use. In this article we explain the concept. The test procedure is on how to do a lactate test.
Rapid response: the lactate threshold is the intensity from which the lactate in blood begins to accumulate. Two points are usually distinguished: the first threshold, when the lactate begins to rise above the resting level, and the second, the highest intensity at which lactate production and elimination are in balance (maximum stable lactate state) (Faude et al., 2009).
What is lactate
Lactate occurs continuously, also at rest. By increasing the intensity, production grows faster than the body eliminates it and the concentration in blood rises. Lactate is not "the culprit" of fatigue: it is a useful indicator of how metabolism responds to effort.
First and second threshold
| Point | Which indicates | Approximate feeling |
|---|---|---|
| First threshold (LT1, aerobic threshold) | The lactate begins to rise above baseline values | Comfortable and sustained pace; you can talk |
| Second threshold (LT2, anaerobic threshold, MLSS) | Higher intensity with stable lactate | Demanding; short sentences |
These two points are often used to divide training into three zones: below the first, between the two and above the second (Seiler, 2010).
What about 4 mmol/l?
A classic criterion is to set the threshold at a fixed concentration of 4 mmol/l (Heck et al., 1985). It is simple, but it does not take into account individual differences: in some athletes the actual threshold is above or below. The review by Faude et al. (2009) collected 25 different threshold concepts and grouped them into three families: fixed concentrations, first rise in lactate and maximum stable state estimates.
How it is estimated
- Laboratory: incremental test with blood intakes at each step to plot the lactate curve.
- Field with lactatometer: the same principle, on track or roller.
- Without lactate: tests of sustained pace or power (e.g. a 30-minute test) or ventilation (ventilatory thresholds). They're approximations.
Each method gives somewhat different results and are not interchangeable: choose one and always use it with the same athlete (Jamnick et al., 2020).
How to use the threshold for training
- Define your zones from the thresholds. We explain it in zones by HR and power.
- Do most of the volume below the first threshold (Seiler, 2010).
- Repeat the rating when you change your shape or start a new block.
Save your thresholds in TrainingForever
In TrainingForever, the coach records the test as a session and decides whether to update the areas of the athlete. With TrainingForever, your coach has all the features free up to 5 athletes; from there, 0.99 € per active athlete per month, with a maximum of 49 €/month. For the athlete it's always free.
What a Coach Says
"For me the threshold is not a fixed number: it is a reference that I review when the athlete changes his form." — Marc Bañuls, coach with more than 15 years of experience
Frequently Asked Questions
What is the lactate threshold?
The intensity from which the lactate in blood begins to accumulate. A first and a second threshold are usually distinguished.
Lactate threshold and anaerobic threshold are the same?
Normally "anaerobic threshold" is used for the second threshold, close to the maximum stable state of lactate. The term is discussed, so it's worth saying what threshold you're talking about.
Can you tell the threshold without a blood test?
It can be estimated with tests of sustained pace or power, or with ventilation, but are approximations.
How often should I repeat the test?
When you change your shape or when you start a new block, always with the same method.
Sources
- Faude O, Kindermann W, Meyer T. Lactate threshold concepts: how valid are they? Sports Med. 2009;39(6):469-90.
- Heck H, et al. Justification of the 4-mmol/l lactate threshold. Int J Sports Med. 1985;6(3):117-30.
- Jamnick NA, Pettett RW, Granata C, Pyne DB, Bishop DJ. An examination and criticism of current methods to determine exercise intensity. Sports Med. 2020;50(10):1729-56.
- Seiler S. What is best practice for training intensity and duration distribution in duration athletes? Int J Sports Physiol Perform. 2010;5(3):276-91.
