The influence of the regression model and final speed criteria on the reliability of lactate threshold determined by the Dmax method in endurance-trained runners.

Few studies verified the reliability of the lactate threshold determined by Dmax method (LT) in runners and it remains unclear the effect of the regression model and the final speed on the reliability of LT. This study aimed to examine the test-retest reliability of the speed at LT in runners, considering the effects of the regression models (exponential-plus-constant vs third-order polynomial) and final speed criteria (complete vs proportional). Seventeen male, recreational runners performed 2 identical incremental exercise tests, with increments of 1 km·h each for 3 min on treadmill to determine peak treadmill speed (V) and lactate threshold.