Lactate threshold

Lactate threshold is used loosely for two points. LT1 (the aerobic threshold, around 2 mmol/L) is where your blood lactate first rises above baseline. LT2 is the highest intensity you can sustain without lactate piling up progressively. LT2 is often approximated two ways. One is OBLA, a fixed cutoff around 4 mmol/L. The other is MLSS, the highest steady-state workload you can hold. These two correlate, but they are not identical, and the absolute values vary by protocol and by person. Training near these thresholds builds mitochondrial enzymes and improves lactate clearance. That raises the workload you can sustain.

Last reviewed: June 22, 2026

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