Blood lactate in trained cyclists during cycle ergometry at critical power

Jenkins, D. G. and Quigley, B. M. (1990) Blood lactate in trained cyclists during cycle ergometry at critical power. European Journal of Applied Physiology and Occupational Physiology, 61 3-4: 278-283. doi:10.1007/BF00357613

Author Jenkins, D. G.
Quigley, B. M.
Title Blood lactate in trained cyclists during cycle ergometry at critical power
Journal name European Journal of Applied Physiology and Occupational Physiology   Check publisher's open access policy
ISSN 0301-5548
Publication date 1990-10-01
Year available 1990
Sub-type Article (original research)
DOI 10.1007/BF00357613
Open Access Status Not yet assessed
Volume 61
Issue 3-4
Start page 278
End page 283
Total pages 6
Place of publication Heidelberg, Germany
Publisher Springer
Language eng
Formatted abstract
The purposes of this investigation were to determine the validity of critical power (CP) as a measure of the work rate that can be maintained for a very long time without fatigue and to determine whether this corresponded with the maximal lactate steady-state (la(ss,max)). Eight highly trained endurance cyclists (maximal oxygen uptake 74.1 ml · kg-1 · min-1, SD 5.3) completed four cycle ergometer tests to exhaustion at predetermined work rates (360, 425, 480 and 520 W). From these four co-ordinates of work and time to fatigue the regression of work limit on time limit was calculated for each individual (CP). The cyclists were then asked to exercise at their CP for 30 min. If CP could not be maintained, the resistance was reduced minimally to allow the subject to complete the test and maintain a blood lactate plateau. Capillary blood was sampled at 0, 5, 10, 20 and 30 min into exercise for the analysis of lactate. Six of the eight cyclists were unable to maintain CP for 30 min without fatigue. In these subjects, the mean power attained was 6.4% below that estimated by CP. Mean blood lactates (n = 8) reached a steady-state (8.9 mmol · l-1, SD 1.6) during the last 20 min of exercise indicating that CP slightly overestimated la(ss,max). Individual blood lactates during the last 20 min of exercise were more closely related to the γ-intercept of the CP curve (r = 0.78, P < 0.05) than either CP (0.34, NS) or mean power output (r = 0.42, NS). The present investigation has shown that highly trained endurance cyclists can tolerate previously unreported levels of blood lactate during 30 min of exercise at or near their CP. Blood lactates during continuous exercise are higher than at the same work rate during an incremental test. The CP provides a simple and inexpensive means of assessing the exercise intensity which can be maintained continuously, while avoiding the methodological difficulties associated with ventilatory and lactate thresholds.
Keyword Physiology
Sport Sciences
Sport Sciences
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Human Movement and Nutrition Sciences Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 85 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 91 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Wed, 09 Mar 2011, 18:50:12 EST