Blood lactate assessment · London
Blood Lactate Threshold Testing in London
Capillary blood lactate sampling across an incremental protocol
Blood is sampled at every stage of a progressive assessment to establish where lactate begins to accumulate, and what that means for the intensities you train at.
- Price
- £300
- Duration
- 60 to 90 minutes
- Locations
- Liverpool Street · Marylebone
How this is provided
Part of Endurance Performance Profiling.
Blood lactate testing is carried out within the Endurance Performance Profiling at £300, not as a standalone appointment. That is deliberate: a lactate value moves with carbohydrate availability, recent training and the muscle mass involved, so on its own it is easy to misread. Recorded against respiratory data and workload in the same session, it can be placed accurately.
If you searched for lactate threshold testing, this is the assessment that produces it.
What is being measured
Lactate production, clearance and the balance between them.
Lactate is produced continuously during exercise and cleared continuously alongside it. It is a fuel that moves between muscle fibres and between tissues, not a waste product and not the cause of the burning sensation it is usually blamed for. What makes it worth measuring is that the balance between how fast it appears and how fast it is removed changes in a predictable way as intensity rises — and the points at which that balance shifts are the boundaries your training is built between.
At low intensities the two keep pace and blood lactate sits near its resting value. Push harder and there comes a point where it rises clearly above that baseline for the first time. That is the first threshold, and it marks the ceiling of work that is genuinely sustainable for hours rather than merely comfortable for twenty minutes.
Above it, lactate is elevated but still stable — production has risen and clearance has risen with it. That region is where longer race efforts sit. Eventually there is an intensity beyond which clearance cannot keep up at all, and lactate climbs for as long as you continue. That is the second threshold, and the time available above it is measured in tens of minutes.
Both are transitions rather than lines. The body moves across them rather than crossing them, which is why the thresholds are reported here as ranges and why the shape of the curve either side of them carries information that a single number does not.
Lactate curve, LT1 and LT2, and your training zones.
Sampled at the end of every stage, so you get the curve rather than one value. Open any of them for how it is measured and what it changes.
01Your lactate curveEvery stage plotted against running speed or cycling power.
How we measure it
A fingertip sample at the end of each three-minute stage, analysed on an ARKRAY Lactate Pro 2 and recorded against the speed, heart rate and perceived effort of that stage.
Why it matters
A single sample gives one value at one intensity. The curve gives the relationship between intensity and lactate, which is where the useful information sits — two athletes can share a threshold speed and have curves that diverge sharply either side of it.
02LT1 — first lactate thresholdThe upper limit of genuinely low-intensity work.
How we measure it
The first intensity at which lactate rises clearly above your baseline.
Why it matters
In practical terms this marks the upper edge of intensity for long, low-stress work. If easy sessions regularly sit above this intensity, they may accumulate more physiological stress than intended.
03LT2 — second lactate thresholdEstimated from the shape of your individual lactate curve.
How we measure it
Where lactate production begins to outpace clearance, identified from the shape of your own curve.
Why it matters
The anchor for threshold and interval prescription. A fixed 4 mmol/L value is a convention that suits some athletes and misrepresents others, so your threshold may sit above or below it.
04The region between themHow wide your tempo band is, and how sharply the curve rises.
How we measure it
From the gradient of the curve either side of each threshold.
Why it matters
Lactate is elevated but stable here, which makes it the region most relevant to longer race efforts. How wide the band is changes how training should be distributed across it.
05Training zonesHeart rate, and running speed or cycling power, for every band.
How we measure it
Derived from your own thresholds, which are reported as ranges rather than single points because both are regions the body moves across rather than fixed lines.
Why it matters
Sessions can be prescribed in the units you already train with. These are starting points; how they are applied depends on your event and the time before it.
06A retest referenceThe values worth tracking so a later curve means something.
How we measure it
The full stage table — lactate, heart rate, workload and effort for each stage — so the raw values are available, not only the conclusions.
Why it matters
Across a retest, a curve that shifts to the right at the same lactate values shows the same internal response now happening at a higher speed or power.
Why it is not sold alone
Two threshold systems, one protocol.
Gas exchange identifies two thresholds as well, from your breathing rather than your blood. Broadly the ventilatory thresholds correspond to the lactate thresholds — they are two independent readings of the same underlying transitions, taken through different windows.
Where the two agree, a threshold is supported by two measurements that do not share a source of error, and the zones drawn from it can be held with more confidence than either alone would justify. Where they diverge, that divergence is information rather than a fault: it can reflect the protocol, your training background, or simply that a gradual transition has been sampled at slightly different points by two methods.
This is the reason blood lactate is carried out inside the Endurance Performance Profiling rather than as an appointment of its own. A lactate value moves with carbohydrate availability, recent training load and how much muscle mass the exercise involves. Read on its own it is easy to misplace. Read against respiratory data recorded at the same stage, on the same day, in the same person, it can be placed properly.
It is also why the preparation matters more here than for most assessments. Pre-test nutritional state can alter substrate availability and the blood-lactate response at a given workload, and a hard session the day before adds a second source of variation. Standardising both is what lets a threshold describe your training rather than your last few days, and it is what makes two assessments comparable.
Sampled at every stage and read against your breathing at that same stage — where the two agree, the threshold is well supported.
Measured with
- ARKRAY Lactate Pro 2 — fingertip sample analysed at every stage
- KORR CardioCoach MAX — respiratory data recorded alongside
- Treadmill or cycle ergometer — you test in the mode you train in
Lactate sampling is built into the progressive assessment rather than performed separately.
- 01IntakeTraining background, recent load and target event, which set the starting intensity.
- 02SetupAnalyser calibrated, mask fitted, heart-rate strap on, sampling kit prepared.
- 03Stage oneThe protocol starts easy, and the first sample establishes your baseline.
- 04The stagesIntensity rises each stage with a sample at the end of every one, building the curve point by point.
- 05ReviewThe plotted curve, LT1 and LT2, and your zones, on screen before you leave.
Endurance athletes who train by zones.
Suited to
- Runners, cyclists and triathletes who train by zones and want them set from measured values
- Athletes whose heart-rate zones do not seem to match how sessions feel
- Athletes preparing for an event where sustained pacing decides the outcome
- Anyone whose easy sessions may be sitting too close to their tempo sessions
- Athletes retesting to see whether a training block has moved the curve
Less suited to
- Athletes in sports decided by short maximal efforts rather than sustained intensity
- Anyone looking for a single number without the context that makes it usable
If you are unsure whether threshold information alone answers your question, ask before booking.
More on thresholds.
Questions we get asked.
Carbohydrate availability influences lactate values, so preparation matters more here than for most assessments. Fast for at least four hours, because resting metabolic rate is measured before the test starts, and avoid an unusually low-carbohydrate day beforehand as it changes the curve. Avoid intense training the day before — recent hard training affects lactate values independently of your fitness. Arrive well hydrated, in the kit and footwear you train in.
No. Blood lactate sampling is performed as part of the Endurance Performance Profiling, at £300. There is no separate lactate-only appointment. The lactate profile is the first of the two tests in that assessment, and the values are more useful read against the respiratory data from the maximal test that follows it.
One at the end of each three-minute stage. You straddle the treadmill belt for about thirty seconds while the sample is taken, then start the next stage. The number of stages depends on your starting speed and how far the profile runs, so the total varies between athletes.
A fingertip prick, comparable to a blood glucose test. It is brief, and athletes commonly report that the effort of the later stages is more demanding than the sampling.
Not necessarily. A fixed 4 mmol/L value is a convention that suits some athletes and misrepresents others. Your second threshold is identified from the shape of your own curve and read against your respiratory data, which is why a threshold reported for you may sit above or below that figure.
Not reliably. Devices that estimate lactate from other signals produce a prediction rather than a measurement. This assessment samples blood directly at each stage.
How abruptly lactate begins to accumulate once the first threshold is passed, and how wide the region between the two thresholds is. Two athletes with the same threshold speed can have very differently shaped curves, and the training implications differ.
Yes. The threshold intensities are expressed in heart rate and in running speed or cycling power, so sessions can be prescribed in the units you train with.
For many training blocks, around 12 to 16 weeks is a useful interval, but the right timing depends on what you are trying to change, the training phase you are in and whether the retest is likely to affect a decision. Lactate values respond to training, but also to carbohydrate availability and recent load, so a shorter interval risks measuring the last few days rather than the last few months.
No. That association is long-standing and wrong. Lactate is a fuel that moves between muscle fibres and between tissues, and it is produced continuously rather than only when you are working hard. The burning sensation during hard exercise has other causes. What lactate is useful for is as a signal: the intensity at which its appearance starts to outpace its removal marks a real transition in what your body can sustain.
For anything raced over more than a few minutes, the fraction of your maximum you can sustain does more to determine the result than the maximum itself. Two athletes with the same ceiling can race very differently if one holds a higher share of it for longer. The maximum is worth knowing; the thresholds are what training is prescribed against.
It happens, and it is reported rather than averaged away. A divergence can reflect the protocol, your training background, or a genuinely gradual transition being sampled at slightly different points by two methods. What it usually means in practice is that the threshold is a wider region for you than for someone whose two systems align tightly — which is itself worth knowing when zones are being set.
Yes, and for a triathlete it is worth doing both. Thresholds are mode-specific: the same athlete can have meaningfully different threshold heart rates cycling and running, so a single set of zones applied across both disciplines will be wrong for at least one of them.
Book Endurance Performance Profiling.
- Price
- £300
- Duration
- 60–90 minutes
- Locations
- Liverpool Street · Marylebone
Where
- UNTIL Liverpool Street280 Bishops Square, London EC2M 4RB
- UNTIL Marylebone1 Orchard Street, London W1H 6HJ
Both sites operate by appointment. Your location is selected when you book.