Methods for estimating the maximal lactate steady state in trained cyclists.
OBJECTIVE
Maximal lactate steady state (MLSS) is the highest exercise intensity at which blood lactate concentration (HLa) remains stable. In this study, we examined the validity of simulated 5-km and 40-km time trials (TT) as methods for estimating average speed at MLSS in cyclists.


METHODS
Nine trained cyclists reported to the laboratory for five to seven exercise trials. Testing included a VO2max test, a simulated 5-km and 40-km TT, and several 30-min MLSS trials.


RESULTS
Mean VO2peak was 4.42 +/- 0.13 L.min-1, whereas VO2 at MLSS (N = 8) was 3.54 +/- 0.15 L.min-1, representing 80.1 +/- 4.1% of VO2peak. HR and HLa at MLSS were 174.7 +/- 2.6 b.min-1 and 6.9 +/- 0.8 mM, respectively. MLSS speed was 36.8 +/- 1.0 km.h-1, which corresponded to 92.1 +/- 1.2% of 5 km average speed (AVS5km). Mean AVS, HLa, and HR during the 40-km TT were 36.6 +/- 0.9 km.h-1, 6.3 +/- 0.7 mM, and 174.1 +/- 2.1 b.min-1, respectively, and did not differ from those at MLSS.


CONCLUSIONS
Both the (simulated) 5-km and 40-km TT can be used to estimate the MLSS in cyclists. In addition, HLa at MLSS shows a large degree of variation between riders.
Harnish
C R
CR
Department of Exercise Science, School of Public Health, University of South Carolina, Columbia, SC, USA. crharnish@earthlink.net
Swensen
T C
TC
Pate
R R
RR
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D012680:Sensitivity and Specificity; D013997:Time Factors
D019344:Lactic Acid