Noninvasive estimation of the maximal lactate steady state in trained cyclists

Purpose: The purposes of this study were to estimate noninvasively the maximal lactate steady state (MLSS) in trained cyclists on a windload simulator with a velocity based technique and to determine whether the HR at MLSS (HRMLSS) elicited a similar blood lactate concentration (BLC) during field testing. Methods: To determine and verify MLSS, 10 male cyclists performed five to seven laboratory trials on separate days, including a (V) over dot O-2max test; a 5-km time trial (TT); and two or more 30-min trials at specific percentages of each subject's average 5-km TT speed (AVS(5km)). Mean +/- SD for the following variables were obtained at MLSS: velocity was 90.3 +/- 2.7% of the AVS(5km), BLC was 5.4 +/- 1.6 mM, RPE was 15 +/- 2.1, (V) over dot O-2 was 80 +/- 6.3% of (V) over dot O-2max, and HR was 167 +/- 9.5 beats.min(-1), which was 88 +/- 3.8% of the mean maximum HR. Field tests included three laps of an 8-km road circuit at HRMLSS +/- 3 beats.min(-1) and one lap at maximum sustainable velocity (a road TT). Results: There were no significant differences in BLC, HR, and RPE between the three steady-state road laps and the lab MLSS trial. There was also good agreement between the road and lab MLSS velocity/TT velocity ratios. Conclusions: Our data suggest that 5-km TT cycling velocity, as measured on a windload simulator, may be used to estimate MLSS and the IIR at MLSS for training purposes.