Long-distance triathlon glossary·LC

Lactate clearance: active lactate removal during effort

Load

The rate at which your body removes produced lactate, determining how long you can sustain a high intensity.

Lactate is not waste: it is fuel. When you exceed your lactate threshold (LT2), lactate production surpasses consumption and blood concentration rises (inverted J-curve). Lactate clearance is the ability of your slow-twitch muscles (type I fibers) and heart to re-consume this lactate as energy substrate. Training that improves it: threshold intervals (Z3 sustained, 20-40 min), over-under intervals (Z4/Z2 alternation in 4-6 min blocks), and plain endurance volume increasing mitochondrial density. In triathlon, good lactate clearance lets you push harder on climb phase 2 without leg burn or irreversible acidification.

In TriPaced:

The TriPaced engine derives your lactate threshold (LT2) from the inflection point of your HR/pace curve on 20-60 min Strava efforts. A high CTL combined with a high FTP/vVO2max generally indicates good lactate clearance. If your Z4 intervals degrade quickly by repetitions 3 and 4, that signals insufficient clearance training.

Source Brooks GA, 1986: The lactate shuttle during exercise and recovery, Medicine & Science in Sports & Exercise

Related terms

  • TSS : Training Stress Score
  • CTL : Chronic Training Load (fitness)
  • ATL : Acute Training Load (fatigue)
  • TSB : Training Stress Balance (freshness)
  • Sweet spot : the efficiency zone
  • Threshold : the upper sustainable limit