Reliability of Maximal Lactate-Steady-State

The aim of this study was the analysis of reliability and day-to-day-variability of power (P-MLSS), blood lactate concentration (BLCMLSS) and heart rate (HRMLSS) in maximal lactate-steady-state during cycle ergometry. 32 male subjects (25 +/- 3 years, 180 +/- 7 cm, 76 +/- 8 kg) have undergone several constant-load-tests lasting 30 min to determine 4 P-MLSS. During the test, blood-samples were taken from the earlobe after 4, 8,10, 14, 18, 22, 26 und 30 min for detecting the BLCMLSS. P-MLSS was defined as the highest workload that can be maintained without accumulation of BLC by more than 0.05 mmol/l/min during the last 20 min. Mean P-MLSS was 244 +/- 45 W, according to 75 % of VO2max. Mean of BLCMLSS was 5.3 +/- 1.5 mmol/l/min, mean of HRMLSS was 166 +/- 10 1/min. The coefficient of variability (CV) was calculated for P-MLSS, BLCMLSS and HRMLSS with 3 %, 16.6 % and 6.3 %, respectively. The Intra-Class-Coefficient for PMLSS, BLCMLSS and for HRMLSS was determined with 0.98 (p <= 0.001), 0.71 (p <= 0.001), 0.92 (p <= 0.001) respectively. P-MLSS and HRMLSS are characterized by a low day-to-day variability that is comparable with results of different lactate threshold concepts. In comparison to P-MLSS, BLCMLSS shows a greater day-to-day-variability.