The lactate minimum test for cycling: estimation of the maximal lactate steady state.

Abstract

This study evaluated the reliability and validity of the lactate minimum test (LMT), an incremental test given after lactic acidosis was induced by sprint exercise. This test is purported to accurately estimate the intensity of exercise at which the transport of lactate into and out of the blood is in equilibrium (maximal lactate steady state or MLSS) and should be a good predictor of endurance performance. Fourteen athletes (mean age 27.2 +/- 3.7 yrs) completed the following on Kreitler rollers: (a) two 20-km time-trials (35.1 +/- 3.3 and 35.7 +/- 3.5 km.hr-1, p < .05); (b) two LMTs yielding lactate minimum speeds (LMS) of 33.6 +/- 3.4 and 33.4 +/- 3.1 km.hr-1 (p > 0.6); and (c) four constant intensity rides, at speeds bracketing the LMS. At 33.5 +/- 3.1 km.hr-1 plasma lactate concentration decreased 0.4 +/- 1.6 mM from 10 to 30 min. Plasma lactate increased 1.6 +/- 0.7 mM while riding 0.9 +/- 0.9 km.hr-1 faster. The LMT is a reliable (r2 = 0.904) and valid method to predict MLSS and a good predictor of endurance performance (LMT vs. 20-km time-trial, r2 = 0.86).