Lactate Threshold

The exercise intensity at which lactate begins accumulating in the blood faster than it can be cleared.

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Understanding Lactate Threshold

Lactate threshold (LT) is the exercise intensity at which lactate accumulates in your blood faster than your body can clear it. Below this threshold, you can sustain effort for a long time. Above it, fatigue builds rapidly and you'll have to slow down within minutes.

Your lactate threshold pace is approximately the pace you could race for 60 minutes — close to your 15K to half marathon race pace for most runners. It's arguably the most trainable of the three key performance metrics (VO2 max, LT, and running economy) and the most predictive of distance racing performance.

Tempo runs and cruise intervals are the primary workouts for raising lactate threshold. By running at or near threshold intensity, you train your body to produce less lactate at a given speed and clear existing lactate more efficiently. The result: your "comfortably hard" pace gets faster over weeks and months of consistent threshold training.

Key Facts: Lactate Threshold

Key facts and insights about lactate threshold that every endurance athlete should know.

LT pace ≈ your ~60-minute race pace

LT pace ≈ your ~60-minute race pace (roughly between 10K and half marathon pace)

Expressed as a percentage of VO2 max

Expressed as a percentage of VO2 max: untrained ~60%, trained ~75–85%, elite ~85–90%

Also called anaerobic threshold, OBLA

Also called anaerobic threshold, OBLA (onset of blood lactate accumulation), or LT2

Lab-tested via blood draws at increasing

Lab-tested via blood draws at increasing exercise intensity (blood lactate >4 mmol/L = threshold)

Pro Tips: Lactate Threshold

Estimate LT pace: 25–30 seconds per mile slower than 10K pace, or 15–20 seconds faster than half marathon pace

One quality threshold session per week (tempo run or cruise intervals) is enough

Threshold effort feels "comfortably hard" — you can speak in short phrases but not full sentences

Consistent easy running (Zone 2) also improves lactate clearance by building aerobic capacity

Frequently Asked Questions About Lactate Threshold

VO2 max is your aerobic ceiling — the maximum oxygen you can use. Lactate threshold is the percentage of that ceiling you can sustain. A runner with a VO2 max of 60 who can sustain 85% of it (LT at 51) will outperform a runner with VO2 max of 65 who can only sustain 70% (LT at 45.5). Threshold is more trainable and more predictive of race performance.

Noticeable improvement in 4–8 weeks of consistent threshold training. Your tempo pace may drop 10–20 seconds per mile over a 12–16 week training cycle. Threshold responds well to training at any level — beginners and veterans alike can shift it meaningfully.