Find Your Lactate Threshold Without a Lab — 3 Methods

"You have to know your anaerobic threshold or you're training wrong." You hear this constantly. But going to a lab for your lactate threshold — that costs $100–200 and eats a whole day. Can you do it without?

Yes, you can. In this article I'll show you three methods — from a simple self-test to your own step test with a lactate meter — and who each one is for.

First: what is the lactate threshold anyway?

In practice, two thresholds matter:

• LT1 (aerobic threshold) — from here blood lactate rises measurably, typically around 2 mmol/L. It's the upper limit of the purely aerobic zone.
• LT2 (anaerobic threshold, MLSS) — from here your body can no longer clear lactate as fast as it's produced, typically around 4 mmol/L. This is the critical threshold for race training.

LT2 is what most people mean when they say "lactate threshold." It sits very close to FTP (on the bike) or your 1-hour race pace (running). How to deliberately steer training just below this threshold is shown by the Norwegian Method — the system behind Jakob Ingebrigtsen.

Method 1: Talk test (free, imprecise, usable)

The simplest test in the world. While training, you try to speak:

• Full sentences, no breathing pauses: well below LT1 (= Z1/Z2)
• Short sentences with breathing pauses: near LT1, the LT1 zone
• Only 2–3 words between breaths: between LT1 and LT2 (tempo zone)
• Speaking no longer possible: above LT2 (race pace and beyond)

Pros: free, instantly available, internal body feedback. Cons: not reproducible between days, imprecise, can be distorted by hyperventilation or nasal breathing. Gives no concrete HR/pace/watt values.

Who should use it: recreational athletes without a power meter or HR monitor, or as a daily check that you're really running easy (a common mistake: the "easy run" turns into too fast).

Method 2: Conconi test (HR monitor / power meter, medium accuracy)

A step test with heart-rate recording. You start very slowly and increase pace/watts every 200m (or every 30s). HR rises linearly with intensity — up to a point where the linear rise ends. This "Conconi deflection" marks the anaerobic threshold (LT2).

Protocol for running:

• 15-min easy warm-up
• Start at 6:30/km
• Every 200m: 5 sec/km faster (so after 200m: 6:25/km, after 400m: 6:20/km, etc.)
• Keep increasing until you can't anymore
• Note HR and pace every 200m / record on Strava

Evaluation: plot HR against pace. Where HR stops rising linearly — often visible as a "flattening" — is your LT2.

Pros: cheap (just an HR monitor), reproducible under equal conditions, gives concrete HR/pace values. Cons: the Conconi deflection isn't clearly detectable in some athletes. Scientifically debated. Weather and day-form strongly affect the result. Requires disciplined step adherence.

Who should use it: recreational athletes with an HR monitor who need a first concrete zone anchor. Accuracy is enough for training guidance, not for race pacing to 1%.

Method 3: Step test with a lactate meter (highest accuracy)

The real deal. A lactate meter (Lactate Plus, Lactate Scout, EKF) costs a one-time $150–300, test strips about $2–3 per measurement. With it you do:

• 5-step test: each step 4–5 minutes at increasing intensity (running example: 6:00/km, 5:30/km, 5:00/km, 4:30/km, 4:00/km)
• Break between steps: 30 seconds, blood sample from earlobe or fingertip
• Measure lactate at each step + note HR + pace/watts

Evaluation: plot lactate values against intensity. LT1 = slight rise above baseline (~2 mmol/L), LT2 = steep rise (~4 mmol/L or via the Dmax method). There are two evaluation methods:

Fixed-value method (2 / 4 mmol)

Classic: LT1 = intensity at 2 mmol, LT2 = intensity at 4 mmol. Simple, reproducible, well-established. But: not everyone has their "true" LT2 at exactly 4 mmol. Endurance-trained athletes often have a lower LT2 (3.5 mmol), powerful ones higher (5 mmol).

Modified Dmax method

Mathematically more precise: you draw a line between the first point with lactate > 0.5 mmol above baseline and the last point. The point on the lactate curve that is furthest from this line defines LT2 individually. Once you have your step-test values and want to compare the fixed-value and Dmax methods side by side, use the interactive lactate analyzer — it computes all models in parallel and plots the curve.

Pros: gold standard outside the lab. Gives both LT1 and LT2, individually calibrated. Cons: one-time $150–300 investment, every measurement costs material, the test takes 30–40 min, needs discipline and practice.

Who should use it: coaches managing several athletes (it pays off fast), ambitious recreational athletes who train seriously, triathletes with long-term race goals.

From test to training zones

Whatever the method — what really matters is what you do with the value. From LT1 and LT2 you derive a 5-zone model used in every serious training plan:

Doing 80% of your training in Z1/Z2 and 20% in Z3–Z5 follows the "polarized training" approach — now established as the best concept for endurance sport (Stephen Seiler, the Norwegian cross-country ski team).

Conclusion

You don't need a lab to train sensibly by zones. For most recreational athletes a combination of the talk test (daily) and a Conconi test every few months is enough. If you make the leap to serious training (marathon < 3:30, middle-distance triathlon), the lactate meter is worth it.

The most important takeaway from all of this: most athletes train their easy sessions too fast and their hard ones too slow. Fixing that makes you better — more than any 0.1-mmol optimization of your thresholds ever will.