Comparison and Performance Validation of Calculated and Established Anaerobic Lactate Thresholds in Running.

: This study aimed to compare the calculated running velocity at the anaerobic lactate threshold (cLT), determined by a mathematical model for metabolic simulation, with two established threshold concepts (onset of blood lactate accumulation (OBLA; 4 mmol∙L) and modified maximal deviation method (mDmax)). Additionally, all threshold concepts were correlated with performance in different endurance running events. : Ten sub-elite runners performed a 30 s sprint test on a cycle ergometer adjusted to an isokinetic mode set to a cadence of 120 rpm to determine maximal lactate production rate (VLa), and a graded exercise test on a treadmill to determine maximal oxygen uptake (VO). Running velocities at OBLA, mDmax, and cLT were then compared with each other, and further correlated with running performance over various distances (3000 m, 5000 m, and 10,000 m). : The mean difference in cLT was -0.13 ± 0.43 m∙s and -0.32 ± 0.39 m∙s compared to mDmax ( = 0.49) and OBLA ( < 0.01), respectively. cLT indicated moderate to good concordance with the established threshold concepts (mDmax: ICC = 0.87, OBLA: ICC = 0.74). In comparison with other threshold concepts, cLT exhibited comparable correlations with the assessed running performances (cLT: = 0.61-0.76, mDmax: = 0.69-0.79, OBLA: = 0.56-0.69). : Our data show that cLT can be applied for determining endurance performance during running. Due to the consideration of individual physiological profiles, cLT offers a physiologically justified approach to assess an athlete's endurance performance.