The number you take home depends on the protocol and on which lactate definition you mark. Keep both the same when you retest, and write them on the sheet.
At a glance
- No hard session in the previous 24–48 hours. Record food, caffeine, and the time of day.
- Optional resting sample, then a 10–15 minute warm-up.
- Stages of 4 minutes (3–5 minutes is the usual range). No rest between stages.
- Start at an easy pace. Add about 1 km/h each stage.
- Sample in the last 30 seconds. Log pace, lactate (mmol/L), heart rate, RPE, and time.
- Stop once the curve is clearly past 4 mmol/L, or when you can no longer hold the pace.
- Print the sheet before you start. A helper makes the samples much cleaner.
Who it's for
Runners who want a field estimate of lactate threshold, to set training paces from their own blood curve rather than from a race formula. You need to be able to run continuously through the warm-up and roughly 25–40 minutes of stages, and to hold a pace on purpose.
A helper is worth arranging. Solo testing is workable on a treadmill and awkward on a track. This is a poor fit if you have no way to know your pace, or if you cannot get a clean sample while the stage is still going.
The result is an estimate tied to this procedure. It is not a laboratory lactate test and it is not a medical assessment. For the physiology behind the curve, see what lactate threshold is.
What you need
- Handheld lactate meter that reports mmol/L (a Lactate Plus or similar), plus 12–15 strips. Rest, the stages, a miss, and a spare all consume strips. Check the expiry, and close the vial.
- Lancets and a lancing device. A fresh lancet for the test.
- Alcohol wipes and dry gauze. Alcohol cleans. Gauze or tissue has to be dry, because you will wipe sweat and throw away the first drop.
- A towel. Sweat on the skin is the usual reason a field sample reads high.
- Heart-rate monitor. A chest strap is more reliable than a wrist sensor when you are gripping a rail or sweating hard.
- Treadmill, or a 400 m track plus a watch that can show lap pace. GPS pace on a treadmill is not useful. On the track, lap pace is steadier than instantaneous pace.
- The data sheet and a pen, or a helper logging on a phone. A sharps container for the lancet. Spare meter batteries.
- A helper, if you can get one. Sampling while you keep running is the weak point of a solo test. A fan is worth having indoors.
Follow the meter’s own strip insert for error codes, control solution, and the temperature range. If you test in the cold, keep the meter and the vial inside a layer until you use them.
Before the test
Lactate and heart rate move with fatigue, fuel, caffeine, heat, and time of day. Standardize what you can, and write down what you did. A retest only compares if those notes match.
- 24–48 hours easy. No intervals, tempo, long hard run, or race. A hard session can move heart rate and lactate, and not always in the same direction. Show up rested, or at least equally rested, next time.
- Fueling. Test fed or fasted, and pick the one you will repeat. If you eat, finish the main meal a couple of hours before so you are not running on a full stomach. A small familiar snack is fine if you record it. Carbohydrate availability can change the lactate response, so “same breakfast” matters more than a perfect breakfast.
- Caffeine. Your usual dose, or none. Write the amount and when you took it. Caffeine can change perceived effort and heart rate. Match it on the next test.
- Hydration. Drink normally through the day. A large bolus in the last few minutes mostly creates a bathroom stop.
- Time of day. Heart rate and the pace you can hold drift across the day. Test at a time you can repeat.
- If you are ill, unusually sore, or short on sleep, postpone. That test becomes a bad training zone.
Write these down before stage 1: temperature, indoor or outdoor, treadmill model or track, grade, hours since the last hard session, what you ate, caffeine, and the sample site. If you track your cycle and want comparable tests, note the phase as context, not as a correction factor. Use the same treadmill when you retest. Displayed belt speed is often a little off, and a different machine is a different test.
Warm-up
- Optional resting sample. Sit quietly for about five minutes first. Lance, discard the first drop, and record the value. Resting capillary lactate often sits somewhere around 0.5–2 mmol/L. You are recording your baseline, not matching a textbook.
- 10–15 minutes very easy, slow enough for full sentences, at or slower than the pace you plan for stage 1.
- Three strides of about 15–20 seconds, building only to the effort you expect in the middle stages, with a full easy minute between them. These are openers, not repeats.
- Two to three minutes easy, then start stage 1. Don’t sit down for long between the warm-up and the first stage.
An end-of-warm-up sample is optional. If you take one, label it “warm-up” and don’t treat it as a stage. The resting sample, if you want one, comes before the strides.
The stages
Swipe the table sideways on a small screen.
| Setting | What to do |
|---|---|
| Stage length | 4 minutes is the default. Anywhere from 3 to 5 minutes is a normal running field choice. Use one length for every stage and every retest. Three minutes is easier to finish, but lactate may not have leveled off, which can push a fixed 4 mmol/L marker to a faster pace. Five minutes sits closer to a steady value and costs more fatigue. Don’t mix lengths inside one test. |
| Start | Easy, full sentences. If you know a pace you could hold for about an hour, start about 1.5–2.5 km/h slower than that. If you don’t, start at easy-run pace. Many recreational runners land between about 7 and 10 km/h; faster runners start faster. Stage 1 lactate should still be close to your resting value. If it is already well above baseline, the next test starts slower. |
| Step | +1.0 km/h each stage. Use +0.5 km/h if you want a tighter curve and can spend the extra strips and time. On a treadmill in miles per hour, 1 km/h is about 0.62 mph, so a step of 0.5–0.6 mph is the practical equivalent. On a track, program the paces into a watch or have a helper call splits. The minutes-per-kilometer change that equals 1 km/h is larger when you are slower (around half a minute per kilometer near 8–9 km/h, and closer to 15–20 seconds per kilometer near 14–16 km/h). Let the watch do that math. |
| Grade | Pick 0% or 1% and leave it. A 1% treadmill grade is a common stand-in for outdoor air resistance. The match is approximate. Changing it between tests matters more than which one you pick. |
| When to sample | The last 30 seconds of the stage, while you are still at that pace if a helper can reach a finger or an earlobe. A sample taken after you have been standing around can drift, especially late in the test, when lactate keeps leaving the muscle. |
| What to record | Stage, pace or speed, lactate in mmol/L, heart rate (the last 30 seconds, or the value at the sample), RPE, and the clock time. Note a bad strip or a long pause in the margin. |
| Between stages | No rest. The next pace starts on schedule. A short solo sampling pause is extra time. Keep it under about 30 seconds and the same length every stage, including the easy ones. |
With a helper
This is the version to use if you can. With about 45 seconds left, the helper dries the site and inserts a strip so the meter is waiting. In the last 30 seconds they lance, wipe the first drop, and fill the strip while you hold the pace. They call out the number. You, or they, write pace, lactate, heart rate, RPE, and the time. The next stage starts on the minute.
On your own
On a treadmill, straddle the belt only long enough to dry, lance, discard the first drop, and fill the strip. Aim for under 30 seconds, then start the next speed and get back on. On a track, a helper really is the better plan. If you are alone, stop at the same line every stage for a timed 20–30 second sample and leave immediately. Write “paused” on the sheet. Don’t compare a paused test with a no-pause test and call the difference fitness.
When to stop
Stop at the first of these that happens:
- The curve is defined past the second rise. A practical rule for this field test: you have a value at or above 4 mmol/L and one more stage if you can still hold the pace, or a reading around 6 mmol/L or higher with the rise already steep. You are mapping thresholds, not finishing a VO2max test. You do not need readings in the double digits.
- You cannot hold the pace for the full stage. Mark that stage incomplete. Don’t assign the lactate to a pace you only held for a minute.
- Safety. Chest pain, dizziness, confusion, feeling faint, or pain that is not ordinary effort. Stop. If chest pain, fainting, or confusion does not clear, get medical help.
- The meter quits or the strips run out. A curve that never rose is not an LT2. Note it and run a lower start next time rather than inventing a breakpoint.
If you stop because the pace broke while lactate is still flat, the start or the step was too hard. Don’t force a threshold out of a curve that never bent.
How to take the sample
The meter is only as good as the drop. Contamination, not the brand name on the case, is what usually spoils a field test.
- Dry the site. Sweat lactate is often higher than blood lactate, so a wet finger reads falsely high. Use the towel every stage, not only when you remember.
- If you use alcohol, let it dry completely. A wet site dilutes the drop. Alcohol is for cleaning, not for the moment you stick.
- Lance the side of a fingertip, or the earlobe if a helper is sampling while you run. The side of the finger hurts less than the pad and bleeds well.
- Wipe away the first drop with dry gauze. The first drop carries more tissue fluid.
- Let a second drop form. A light stroke from the base of the finger toward the tip is fine. Don’t pinch hard at the puncture. Hard squeezing dilutes the sample and can read low.
- Touch the drop to the strip, not the strip to the skin. Let the strip take what it needs. A bigger puddle is not a better result. If your meter ever reports mg/dL instead of mmol/L, divide by 9. A Lactate Plus already reports mmol/L.
- Write the number down before the meter sleeps. If the strip errors or does not fill, resample once and mark “resample” on the sheet.
- Stay with one site. Fingertip and earlobe can disagree by enough to move a point. You can switch fingers if one stops bleeding. Don’t switch from finger to ear in the middle of the test.
- Put the lancet in a sharps container, not in a pocket and not in the gym trash.
If one value spikes off the trend and the next stage falls back onto the curve, treat the spike as a bad drop. One odd point should not redraw the threshold.
How to read the result
Plot pace or speed on the horizontal axis and lactate on the vertical axis. Then mark a definition on purpose. The same samples support several common markers, and they do not land on the same pace. Comparing a “threshold” from one method with a threshold from another will look like a change in fitness when nothing changed but the ruler.
Swipe the table sideways on a small screen.
| Marker | How to mark it on your plot | What it is, and what it is not |
|---|---|---|
| LT1, first rise above baseline | The first pace where lactate steps up from the early flat values and the next stage is higher still. A blip that falls back down is noise or a bad sample. Labs don’t share one rule: some use a visual rise, some use about 0.5 mmol/L above the lowest point, some use about 1.0. | Often called the aerobic threshold or the first lactate turn point. It is a common top end for easy aerobic running. The delta you choose moves the pace. |
| Fixed 2 mmol/L | Where a horizontal line at 2.0 crosses your curve. Interpolate between the stages on either side. | A convenient line. It is not the same physiological point in every runner, because baselines differ. Some coaches use it as an aerobic marker. It can sit near a first-rise LT1, or a bit away from it. |
| OBLA, fixed 4 mmol/L | Where a horizontal line at 4.0 crosses the curve. Interpolate. | Onset of blood lactate accumulation, in the fixed-concentration sense. Simple and easy to repeat. Often near a second threshold, and not guaranteed to match that runner’s maximal lactate steady state. |
| D-max | Fit a curve. Draw a straight line from the first point to the last. D-max is the point on the curve farthest from that line. A hand sketch is approximate. Perpendicular distance to a smoothed curve is the formal version. | One mathematical estimate. On a curve with a long flat start, original D-max often sits lower than a 4 mmol/L marker. |
| Modified D-max | Same geometry, but the straight line starts where lactate first leaves baseline, not at stage 1. Spreadsheets don’t all pick that starting point the same way. | Often lands nearer a 4 mmol/L or second-threshold region than original D-max. It still depends on the fit and on which points you include. |
| IAT | You cannot mark a formal individual anaerobic threshold from this step test alone. The strict method uses the rise during the test and the way lactate clears afterward. | Don’t label a visual bend “IAT” unless you actually ran that method. You can mark a visual LT2 and call it that. |
| Visual LT2 | Where the curve bends from a shallow rise into a steep one, after LT1. | A practical field marker when you are not fitting a curve. Maximal lactate steady state — the hardest pace where lactate would stay nearly flat over a long bout — is the idea LT2 is aiming at. Confirming MLSS takes several constant-pace sessions. One step test only estimates that neighborhood. |
The phrase “anaerobic threshold” has been used for several of these markers. Prefer the specific name on your sheet. Stage length, finger versus earlobe, a sampling pause, and whether you ate all move the points. Handheld meters are also noisier than a bench analyzer. A wiggle of a few tenths that comes back on the next stage is not a new threshold.
Interpolation
Stages rarely land on exactly 2.0 or 4.0. If 14 km/h reads 3.4 and 15 km/h reads 4.8, then 4.0 is (4.0 − 3.4) / (4.8 − 3.4) = 0.6 / 1.4 of the way from 14 to 15, about 14.4 km/h. Do the same arithmetic every retest. Don’t round to the nearest whole stage and then compare tests that rounded in opposite directions.
An example curve
These speeds and lactates are made up so the definitions can be compared on one picture. They are not a target, not a population average, and not a zone prescription.
On this example the early values sit around 1.1–1.5 mmol/L through 11 km/h. A visual first rise is at 12 km/h (1.9 mmol/L), because the next stage keeps climbing. A baseline-plus-1.0 rule, 1.1 + 1.0 = 2.1, falls between 12 and 13 km/h, near 12.3. A fixed 2.0 line is about 12.1 km/h. Three ways of saying “LT1,” three slightly different paces.
A fixed 4.0 line is about 14.4 km/h, using the interpolation above (3.4 at 14 km/h, 4.8 at 15 km/h). A hand sketch of original D-max, judging the biggest vertical gap from a line that joins the first point to the last, sits lower, around 13–14 km/h. Starting that line at the first rise (a modified D-max sketch) moves the marker up near 14 km/h, closer to 4 mmol/L and not identical to it. A formal curve fit will not land on those exact decimals. The lesson is the disagreement, not the third digit.
Zones from your test
Swipe the table sideways on a small screen.
| Zone | Name | How to set it | What it’s for |
|---|---|---|---|
| 1 | Recovery | Clearly easier than LT1. Use a pace that still looked like the flat baseline stages. | Recovery days, when the point is to absorb work. |
| 2 | Endurance | From recovery up to the LT1 pace you marked. | Long aerobic running. |
| 3 | Tempo | Above LT1 and below the LT2 band. | Steady, comfortably hard running. |
| 4 | Threshold | A narrow band at the LT2 pace. With stage-sized resolution, that means the LT2 pace and, if you want a range, the stage just slower. | Threshold repeats. |
| 5 | Above threshold | Faster than LT2. | Short intervals. Lactate will accumulate. That is the point of the zone, and it is not a place to live. |
Prescribe pace. Copy the heart rate you logged at the closest stage and use it as a check. Heart rate drifts up over a long session, and it sits higher in the heat, so a value from minute 4 of a stage is often lower than the heart rate late in a long rep at the same pace. Don’t rebuild the zones from a hot day’s heart rate and keep the pace from a cool day’s test without noticing you did that.
Afterward, plot the curve before you pick the zones, eat the way you would after any hard session, and compare only with a previous test that used the same stage length, step, sample site, nutrition pattern, and definition.
Data sheet
Running lactate step test
Print this page before the test. The blank sheet starts on a new page, with room to write. Fill conditions before stage 1, the stage rows during the test, and the markers after you plot.
| Date | |
|---|---|
| Time of day | |
| Place and grade | |
| Temperature | |
| Fed or fasted | |
| Caffeine | |
| Hours since hard session | |
| Meter and strip lot | |
| Sample site | |
| Stage length | |
| Start and step | |
| Sampling pause |
Swipe the table sideways on a small screen.
| Stage | Intensity | Lactate | HR | RPE | Time |
|---|---|---|---|---|---|
| Rest | |||||
| Warm-up | |||||
| 1 | |||||
| 2 | |||||
| 3 | |||||
| 4 | |||||
| 5 | |||||
| 6 | |||||
| 7 | |||||
| 8 | |||||
| 9 | |||||
| 10 |
Intensity is pace or speed. Lactate is mmol/L. RPE is Borg 6–20: 6 is no exertion, 9 very light, 11 light, 13 somewhat hard, 15 hard, 17 very hard, 19 extremely hard, 20 maximal. Time is the clock time at the sample. Add a row if you need an 11th stage.
| Marker | Definition used | Intensity | HR |
|---|---|---|---|
| LT1 | |||
| LT2 |
| Notes |
|---|
This is a practical guide for athletes who already use a handheld lactate meter. It is not medical advice. Capillary sampling involves blood: follow the meter manual, use a fresh lancet, and put used lancets in a sharps container. Skip the test if you are ill. Stop for chest pain, dizziness, or feeling faint. If you use anticoagulant medication, have a bleeding disorder, or have been told to avoid hard tests, check with a clinician before finger-sticking through a hard session.