Reliability of maximal lactate-steady-state

The aim of this study was the analysis of reliability and day-to-day-variability of power (PMLSS), 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 PMLSS. 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. PMLSS 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 PMLSS 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 PMLSS, 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. PMLSS and HRMLSS are characterized by a low day-to-day variability that is comparable with results of different lactate threshold concepts. In comparison to PMLSS, BLCMLSS shows a greater day-to-day-variability.