Higher Accuracy of the Lactate Minimum Test Compared to Established Threshold Concepts to Determine Maximal Lactate...

This study evaluated the accuracy of the lactate minimum test, in comparison to a graded-exercise test and established threshold concepts (OBLA and mDmax) to determine running speed at maximal lactate steady state. Eighteen subjects performed a lactate minimum test, a graded-exercise test (2.4 m·s^-1 start,+0.4 m·s^-1 every 5 min) and 2 or more constant-speed tests of 30 min to determine running speed at maximal lactate steady state. The lactate minimum test consisted of an initial lactate priming segment, followed by a short recovery phase. Afterwards, the initial load of the subsequent incremental segment was individually determined and was increased by 0.1 m·s^-1 every 120 s. Lactate minimum was determined by the lowest measured value (LM_abs) and by a third-order polynomial (LM_pol). The mean difference to maximal lactate steady state was+0.01±0.14 m·s^-1 (LM_abs), 0.04±0.15 m·s^-1 (LM_pol), -0.06±0.31 m·s¹ (OBLA) and -0.08±0.21 m·s¹ (mDmax). The intraclass correlation coefficient (ICC) between running velocity at maximal lactate steady state and LM_abs was highest (ICC=0.964), followed by LM_pol (ICC=0.956), mDmax (ICC=0.916) and OBLA (ICC=0.885). Due to the higher accuracy of the lactate minimum test to determine maximal lactate steady state compared to OBLA and mDmax, we suggest the lactate minimum test as a valid and meaningful concept to estimate running velocity at maximal lactate steady state in a single session for moderately up to well-trained athletes.