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

Background and Objectives: This study aimed to compare the calculated running velocity at the anaerobic lactate threshold (cLT_An), determined by a mathematical model for metabolic simulation, with two established threshold concepts (onset of blood lactate accumulation (OBLA; 4 mmol∙L⁻¹) and modified maximal deviation method (mDmax)). Additionally, all threshold concepts were correlated with performance in different endurance running events. Materials and Methods: 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_max), and a graded exercise test on a treadmill to determine maximal oxygen uptake (VO_2max). Running velocities at OBLA, mDmax, and cLT_An were then compared with each other, and further correlated with running performance over various distances (3000 m, 5000 m, and 10,000 m). Results: The mean difference in cLT_An was −0.13 ± 0.43 m∙s⁻¹ and −0.32 ± 0.39 m∙s⁻¹ compared to mDmax (p = 0.49) and OBLA (p < 0.01), respectively. cLT_An 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_An exhibited comparable correlations with the assessed running performances (cLT_An: r = 0.61–0.76, mDmax: r = 0.69–0.79, OBLA: r = 0.56–0.69). Conclusion: Our data show that cLT_An can be applied for determining endurance performance during running. Due to the consideration of individual physiological profiles, cLT_An offers a physiologically justified approach to assess an athlete’s endurance performance.

Effects of six-week sprint interval or endurance training on calculated power in maximal lactate steady state

The purpose of the study was to evaluate and compare the influence of sprint interval training (SIT) and endurance training (ET) on calculated power in maximal lactate steady state (PMLSS) (influenced by the maximal lactate production rate (⩒La_max) and maximal oxygen uptake (⩒O_2max)). Thirty participants were randomly assigned to the a) SIT, b) ET, or c) control group (n = 10 each). Each session consisted of four to six repetitions of 30 s all-out effort Wingate anaerobic tests (SIT) or 60 min cycling at 1.5 to 2.5 mmol∙L^-1 blood lactate (analysed every 10 min). Both groups performed training on three days per week, over a period of six weeks. To measure ⩒La_max and ⩒O_2max, and to calculate PMLSS, sprint and ramp tests were performed at baseline and after two, four and six weeks of intervention. While SIT resulted in a significant reduction of ⩒La_max (-0.08 ± 0.05 mmol∙L^-1∙s^-1, p=0.003) after two weeks and remained subsequently stable, ⩒O_2max (+2.6 ± 2.4 ml∙min^-1∙kg^-1, p = 0.044) and PMLSS (+25 ± 14 W, p=0.002) increased, but not before six weeks of SIT. After two weeks of ET, ⩒La_max remained unchanged, but ⩒O_2max increased by increased by +2.9 ± 2.4 ml∙min-1∙kg-1, p=0.03, and after six weeks by 5.6 ± 3.5 ml∙min^-1∙kg^-1. The increase of PMLSS was significant after four weeks of ET (+16 ± 14 W, p=0.036) and increased to +32 ± 17 W after six weeks. Comparison of SIT and ET revealed no significant differences for ⩒La_max, ⩒O_2max or PMLSS after six weeks. The control group remained stable in all parameters. In both exercising groups there was a significant improvement of the calculated PMLSS due to different influences of ⩒La_max and ⩒O_2max.

Reliability of the calculated maximal lactate steady state in amateur cyclists

Complex performance diagnostics in sports medicine should contain maximal aerobic and maximal anaerobic performance. The requirements on appropriate stress protocols are high. To validate a test protocol quality criteria like objectivity and reliability are necessary. Therefore, the present study was performed in intention to analyze the reliability of maximal lactate production rate (V.L_amax) by using a sprint test, maximum oxygen consumption (V.O_2max) by using a ramp test and, based on these data, resulting power in calculated maximum lactate-steady-state (PMLSS) especially for amateur cyclists. All subjects (n = 23, age 26 ± 4 years) were leisure cyclists. At three different days they completed first a sprint test to approximate V.La_max. After 60 min of recreation time a ramp test to assess V.O_2max was performed. The results of V.La_max-test and V.O_2max-test and the body weight were used to calculate PMLSS for all subjects. The intra class correlation (ICC) for V.La_max and V.O_2max was 0.904 and 0.987, respectively, coefficient of variation (CV) was 6.3% and 2.1%, respectively. Between the measurements the reliable change index of 0.11 mmol·l ^-1s ^-1 for V.La_max and 3.3 mlkg ^-1min ^-1 for V.O_2max achieved significance. The mean of the calculated PMLSS was 237 ± 72 W with an RCI of 9 W and reached with ICC = 0.985 a very high reliability. Both metabolic performance tests and the calculated PMLSS are reliable for leisure cyclists.