Quick Answer
LT pace = approximately your current 10K race pace (recreational runners); feels “comfortably hard” at 7–7.5/10 RPE; approximately 83–88% of maximum heart rate. Primary session: continuous tempo run of 20–40 minutes. Volume: 15–20% of weekly mileage. Frequency: once per week, twice for half marathon and marathon runners. Retest pace every 4–6 weeks.
What Is Lactate Threshold — and Why It Matters
When you run, your muscles produce lactate as a byproduct of energy metabolism. At easy, conversational paces, your body clears lactate as fast as it produces it — the system stays in balance. As pace increases, lactate production rises. There’s a specific pace at which lactate production and clearance are in rough equilibrium: this is your lactate threshold. Above it, lactate accumulates exponentially, muscles acidify, and running becomes unsustainable within minutes.
Threshold training works by teaching the body to clear lactate more efficiently at a given pace — effectively moving the threshold to a higher speed. When your threshold rises, paces that used to feel “on the edge” now feel controlled, and race paces that previously caused rapid deterioration become sustainable for much longer.
Understanding the two thresholds helps clarify why different types of running produce different adaptations:
Aerobic threshold (~2 mmol/L blood lactate): the first point at which lactate rises meaningfully above baseline. This corresponds to a comfortable running pace — approximately marathon pace for trained runners. Training near this point (easy-to-moderate running, long runs) builds aerobic base and pushes the aerobic threshold upward over time.
Lactate threshold (~4 mmol/L blood lactate): the second, higher threshold — the intensity above which lactate accumulates faster than it can be cleared. This is the “comfortably hard” effort that defines classic threshold training. For recreational runners this corresponds to approximately 10K race pace; for well-trained runners it sits closer to 15K pace; for elite runners it approaches half marathon pace.
The gap between these two thresholds represents a runner’s aerobic development. Closing it — raising the lactate threshold closer to VO2 max pace — is how endurance runners get faster over months and years of structured training.
The relationship between LT and VO2 max is important for understanding what to prioritise by race distance. VO2 max sets your aerobic ceiling — the maximum rate at which your body can use oxygen. Lactate threshold determines how much of that ceiling you can actually use during a race. For 5K racing, VO2 max matters enormously — the race is short enough that ceiling height is the primary limiter. For half marathon and marathon, you’re racing well below your VO2 max ceiling for 1–4 hours; how high your threshold sits determines how fast you can sustain running in that window. Our VO2 max workouts guide covers the complementary training that develops the ceiling; this guide covers how to get closer to it.
How to Find Your Lactate Threshold Pace
Lab testing — running on a treadmill while blood lactate is measured at increasing intensities — provides the most precise LT measurement, but it’s expensive and unnecessary for recreational runners. Four practical methods are accurate enough for training purposes:
By race pace. The most straightforward method. Recreational runners’ LT pace is approximately their current 10K race pace — roughly 15–30 seconds per mile (10–20 seconds per kilometre) slower than 10K effort. If your 10K pace is 5:00/km, your LT pace is approximately 5:10–5:20/km. Well-trained runners (sub-40 min 10K) will find their LT sits closer to 15K pace. Use a VDOT calculator or our running pace calculator with a recent race time to determine your zone.
By feel. LT pace feels “comfortably hard” — a 7 to 7.5 out of 10 on the RPE scale. You can speak a few words if asked a direct question, but holding a conversation would be difficult and distracting. Breathing is clearly elevated and rhythmic but not gasping. You’re working, but you’re in control. Anything easier than this is not threshold stimulus; anything harder risks pushing above LT into VO2 max territory.
By heart rate. LT corresponds to approximately 83–88% of maximum heart rate. If your maximum heart rate is 185 bpm, LT effort falls between approximately 154–163 bpm. Heart rate zones vary individually, so this is a guide rather than a precise prescription — some runners’ thresholds occur at 80% HRmax, others at 91%. Our heart rate zone training guide covers how to determine individual training zones accurately.
By field test. After a thorough 15-minute warm-up, run as far as possible in 30 minutes at the hardest effort you can sustain for the full duration. Your LT pace is approximately the pace you maintained — distance covered ÷ 30 minutes. This test is demanding but gives a direct performance-based measure of your current threshold. Retest every 4–6 weeks as fitness improves, and adjust training paces accordingly.
Important: use your current pace, not your goal pace. Running threshold sessions at a pace you haven’t yet earned means operating above LT — accumulating lactate rapidly, falling apart mid-session, and producing lower-quality work that feels harder without delivering the specific LT adaptation. The same principle applies to threshold training as to VO2 max intervals: current fitness first, progression over time.
The 5 Lactate Threshold Workouts That Work
Workout 1: Continuous Tempo Run (20–40 minutes)
The cornerstone of threshold training. A single, sustained effort at LT pace — no recovery breaks, no pace changes — run for 20 to 40 minutes after a thorough warm-up. Beginners start with 20 minutes; experienced runners build toward 35–40 minutes as fitness develops. The continuous format applies steady pressure to the aerobic system throughout, producing strong adaptation in lactate clearance capacity and the mental ability to hold a hard pace for extended periods. Jack Daniels, one of the most influential running coaches in history, defines tempo pace as a steady run lasting approximately 20 minutes — this is the reference workout against which all other LT formats are measured. For marathon preparation, tempo runs are one of the most race-specific workout types available.
Workout 2: Cruise Intervals (5–15 min reps, 1–3 min recovery)
Cruise intervals break the tempo run into longer chunks with brief recovery jogs between repetitions. The recovery is intentionally short — 1 to 3 minutes — and the goal is not full recovery but rather allowing a brief reduction in systemic lactate before returning to threshold effort. A typical cruise interval session: 3–4 × 8–12 minutes at LT pace with 2 minutes easy jog recovery. This format allows runners to accumulate more total time at LT pace than a single continuous tempo might permit, particularly in the early stages of building threshold capacity. The brief recovery periods do not blunt the LT stimulus — the lactate system remains activated throughout the session — they simply make the workout more psychologically and physically manageable than one long unbroken effort.
Workout 3: LT Intervals (3–8 min reps, slightly above LT)
Shorter, slightly faster than classic threshold pace — approximately 5–10 seconds per kilometre faster than LT pace — with recovery of half the work interval duration. A typical session: 5–6 × 5 minutes at slightly above LT pace, 2.5 minutes easy jog. This format trains lactate buffering capacity — the body’s ability to tolerate higher lactate concentrations before performance degrades — rather than clearance efficiency alone. It’s a more demanding session than cruise intervals and should be used less frequently, sitting closer to the VO2 max end of the intensity spectrum. Particularly useful for 10K runners whose race effort sits near or slightly above LT. Our complete speed work guide covers how this session fits within a broader interval training framework.
Workout 4: Change-of-Pace Tempo (Alternation Runs)
One of the most research-supported but least commonly used LT workout formats. Pace alternates between efforts 2.5–5% faster than LT and 2.5–5% slower than LT, with no rest intervals — the entire session is continuous, but pace oscillates above and below the threshold line. A practical example: alternate 4 minutes at 5–10 seconds per kilometre faster than LT with 4 minutes at 5–10 seconds per kilometre slower than LT, repeated 4–6 times. This format creates fluctuating lactate levels that challenge both production and clearance mechanisms simultaneously. RunningFront’s lactate analysis describes alternation workouts as particularly effective for developing the ability to handle pace surges in racing — the mid-race accelerations and late-race pushes that exceed threshold briefly then return to sustainable effort.
Workout 5: Progression Run (Building into LT)
A progression run begins at easy pace and builds steadily toward LT pace over the course of 45–75 minutes, finishing the final 15–20 minutes at full threshold effort. The structure means the body arrives at LT intensity already warmed, glycogen-primed, and physiologically ready — producing a different LT stimulus than cold-start tempo runs. Progression runs are particularly valuable when built into long runs during half marathon and marathon preparation: the final 15–20 minutes at LT pace on glycogen-depleted legs replicates late-race conditions and builds the specific fitness needed for strong race finishes. Use this format sparingly — once every 2–3 weeks during a marathon build — as it is more fatiguing than a standalone tempo. Our half marathon race week guide covers how to taper appropriately after a heavy LT training block.
How Much Threshold Training: Volume and Frequency
| Runner type | Weekly LT volume | Sessions per week | Primary format |
|---|---|---|---|
| Beginner (under 30km/week) | 5–8km of threshold work | 1 session | 20–25 min continuous tempo |
| Intermediate (30–60km/week) | 8–12km of threshold work | 1–2 sessions | Tempo run + cruise intervals |
| Advanced (60–80km/week) | 12–16km of threshold work | 2 sessions | Tempo + LT intervals or alternation runs |
| Marathon-focused | 15–20% of weekly volume | 2 sessions | Saturday tempo + Tuesday cruise intervals |
Threshold work should constitute approximately 15–20% of total weekly running volume. The remaining 80–85% should be genuinely easy running — not “moderately easy” or “fairly comfortable,” but truly conversational-pace running. This polarised distribution (easy/hard, with little medium-effort running) is validated by both the Norwegian training model and decades of coaching experience. Our easy run effort guide covers exactly what easy should feel like — runners who run recovery days too hard arrive at threshold sessions already fatigued, producing lower-quality work and accumulating injury risk without the specific adaptation.
The Norwegian approach, made famous by runners like Jakob Ingebrigtsen, uses blood lactate meters to train at precisely 2–4.5 mmol/L — the sweet spot where adaptation is maximised and recovery remains rapid enough for high session frequency. Elite Norwegian runners do 3–4 threshold sessions per week. For recreational runners, once per week is sufficient and sustainable; twice per week is appropriate for dedicated event preparation.
Unlike VO2 max intervals, recovery jogs between LT intervals should be short — 1 to 3 minutes maximum. This is not arbitrary. The goal of LT training is to maintain a systemic lactate elevation throughout the session. Extended recovery allows full lactate clearance, removing the specific stimulus that drives LT adaptation. A 5-minute recovery between cruise intervals might feel more comfortable, but it turns the workout into disconnected tempo efforts rather than a true threshold stimulus.
Integrating LT Training Into Your Running Week
For most runners, the optimal weekly structure is: one easy run, one threshold session, one easy or long run, rest or cross-training, one easy run, one VO2 max session or strides session, one long run. The threshold session and VO2 max session should be separated by at least 48 hours of easy running. Sandwiching a threshold session between two easy days ensures quality on both sides.
Adding short strides at the end of easy runs in the days surrounding a threshold session supplements LT training with neuromuscular speed work. Our strides guide covers the 15–20 second acceleration technique that develops leg speed without adding cardiovascular fatigue — a low-cost addition that compounds with threshold training over a training block.
For runners building mileage alongside LT training, the aerobic base is the foundation that allows threshold work to produce its best results. Our guide on building mileage safely covers the gradual volume progression that creates the substrate — mitochondrial density, capillary network, aerobic enzyme levels — that threshold training then optimises. Running high LT volume without the aerobic base beneath it is a short-cut that produces rapid initial gains and rapid subsequent stagnation.
Hill running is an effective threshold training variant that reduces impact stress while producing comparable LT adaptation. LT hill repeats — 3–5 minutes at threshold effort on a 4–6% gradient — develop the posterior chain strength and running economy that makes flat threshold running more efficient. Our hill running guide covers how to structure these sessions and integrate them alongside flat tempo work. For runners concerned about form degradation at threshold effort, our running form guide covers the specific mechanics — forward lean, arm drive, foot strike — that break down most commonly when pace pressure rises.
Lactate clears relatively rapidly after threshold effort — blood lactate returns to near-resting levels within an hour, and even sooner if a short easy run is performed afterward. This means the recovery window for threshold training, while requiring easy running between sessions, does not require the 5–7 day recovery that VO2 max sessions demand. An easy 30-minute jog the day after a tempo run actually accelerates lactate clearance and leaves the legs ready for subsequent quality work sooner than complete rest.
Structure Your Threshold Training Into a Complete Programme
SportCoaching's running training plans sequence tempo runs, cruise intervals, and VO2 max sessions correctly within each training week — the right session, at the right time, with the right recovery on either side.
FAQ: Lactate Threshold Running
What is lactate threshold running pace?
Approximately your current 10K race pace for recreational runners; 15K pace for well-trained amateurs; half marathon pace for competitive runners. Effort-wise: “comfortably hard,” 7–7.5/10 RPE, able to speak only a few words, approximately 83–88% of maximum heart rate.
How do I find my lactate threshold pace without a lab test?
By race pace (approximately 10K pace), by feel (comfortably hard, 7–7.5/10), by heart rate (83–88% max HR), or by 30-minute field test (run as far as possible in 30 minutes; that pace is your LT). Retest every 4–6 weeks as fitness improves and update your training paces accordingly.
How often should I do lactate threshold runs?
Once per week for most runners; twice per week for dedicated half marathon and marathon runners (one continuous tempo, one cruise interval session). Threshold work should represent 15–20% of total weekly mileage, with 80–85% at easy effort.
What is the difference between a tempo run and lactate threshold training?
A tempo run is one specific LT workout format — a continuous 20–40 minute effort at threshold pace. Lactate threshold training is the broader category that also includes cruise intervals, LT intervals, alternation runs, and progression runs. All target the same adaptation through different structures.
Is lactate threshold or VO2 max more important for marathon running?
Lactate threshold. Research shows LT correlates 0.91 with marathon times vs 0.63 for VO2 max in recreational runners. VO2 max sets your aerobic ceiling; LT determines how much of that ceiling you can sustain for 1–4 hours. For distances above 10K, prioritise LT training alongside — not instead of — VO2 max work.
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