Document Detail

The Conconi test in not valid for estimation of the lactate turnpoint in runners.
MedLine Citation:
PMID:  9293415     Owner:  NLM     Status:  MEDLINE    
Conconi et al. (1982) reported that an observed deviation from linearity in the heart rate-running velocity relationship determined during a field test in runners coincided with the 'lactate threshold'. The aim of this study was to assess the validity of the original Conconi test using conventional incremental and constant-load laboratory protocols. Fourteen trained male distance runners (mean +/-s: age 22.6 +/- 3.4 years; body mass 67.6 +/- 4.8 kg; peak VO2 66.3 +/- 4.7 ml kg-1 min-1) performed a standard multi-stage test for determination of lactate turnpoint and a Conconi test on a motorized treadmill. A deviation from linearity in heart rate was observed in nine subjects. Significant differences were found to exist between running velocity at the lactate turnpoint (4.39 +/- 0.20 m s-1) and at deviation from linear heart rate (5.08 +/- 0.25 m s-1) (P < 0.01), and between heart rate at the lactate turnpoint (172 +/- 10 beats min-1) and at deviation from linearity (186 +/- 9 beats min-1) (P < 0.01). When deviation of heart rate from linearity was evident, it occurred at a systematically higher intensity than the lactate turnpoint and at approximately 95% of maximum heart rate. These results were confirmed by the physiological responses of seven subjects, who performed two constant-velocity treadmill runs at 0.14 m s-1 below the running velocity at the lactate turnpoint and that at which the heart rate deviated from linearity. For the lactate turnpoint trial, the prescribed 30 min exercise period was completed by all runners (terminal blood lactate concentration of 2.4 +/- 0.5 mM), while the duration attained in the trial for which heart rate deviated from linearity was 15.9 +/- 6.7 min (terminal blood lactate concentration of 8.1 +/- 1.8 mM). We concluded that the Conconi test is invalid for the non-invasive determination of the lactate turnpoint and that the deviation of heart rate from linearity represents the start of the plateau at maximal heart rate, the expression of which is dependent upon the specifics of the Conconi test protocol.
A M Jones; J H Doust
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Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  Journal of sports sciences     Volume:  15     ISSN:  0264-0414     ISO Abbreviation:  J Sports Sci     Publication Date:  1997 Aug 
Date Detail:
Created Date:  1997-10-23     Completed Date:  1997-10-23     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8405364     Medline TA:  J Sports Sci     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  385-94     Citation Subset:  IM    
Human Performance Laboratory, Chelsea School Research Centre, University of Brighton, UK.
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MeSH Terms
Anaerobic Threshold / physiology*
Analysis of Variance
Exercise Test / standards*
Heart Rate / physiology
Lactic Acid / blood,  metabolism*
Linear Models
Physical Exertion / physiology*
Reference Values
Reproducibility of Results
Running / physiology*
Reg. No./Substance:
50-21-5/Lactic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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