|Lactate threshold (LT, Tlact)||Minimum work rate at which [Lac]b is found, at least in the early minutes, to be significantly above (sometimes defined as 1 mmol: L -1 above) resting value||2|
|Anaerobic threshold (AT)|
- Work rate at which it has been considered that shortfall in oxygen supply to working muscles causes them to begin drawing on anaerobic pathways.
- Previously taken as equating to LT but there is now good evidence that fully aerobic muscles release lactate
|Ventilatory threshold (VT, Tvent)|
- Work rate at which the gradient of the ventilation/work rate plot increases.
- Attributed to rise in [Lac]b so used as non-invasive indicator of LT/AT, but precision of the agreement varies with method of determining VT
|Aerobic threshold||Work rate considered to be minimum for achievement of aerobic training effects (not that at which aerobic metabolism starts, which is of course zero)||2|
|Maximum lactate steady state (MLSS)|
- Highest work rate which can be maintained without continuous rise in [Lac]b (see comment under OBLA).
- Functionally equivalent to critical power ( qv ) though this is defined in terms of O2, not [Lac]b
|Onset of blood lactate accumulation (OBLA)||Work rate at which a continuous rise in [Lac]b begins. (At and a little above LT, it rises only initially, and falls gradually again after a few minutes.) OBLA is thus theoretically slightly above MLSS, but it is doubtful whether they are distinguishable in practice||4|