| Physiological variables at lactate threshold under-represent cycling time-trial intensity. | |
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MedLine Citation:
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PMID: 12391432 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: The importance of lactate threshold (LT) as a determinant of performance in endurance sports has been established. In addition, it has been shown that during running and selected other endurance competitions, athletes perform at a velocity and VO2 slightly above LT for the duration of the event. Prior work indicates however, that this may not be true during a cycling time-trial (TT). This investigation sought to compare physiological variables during a 20-k TT with those corresponding to the athlete's LT. METHODS: Thirteen male cyclists (22.7+/-0.8 yrs; 180.6+/-8.0 cm; 77.1+/-10.0 kg; 8.3+/-2.5% fat; 4.9+/-2.2 l x min(-1), VO2max) participated in the study. Subjects performed a graded protocol starting at 150 Watts (W) to determine LT (2 mmol x L(-1) above baseline) which consisted of 20 W increases every 4-min. Following an 8 min-recovery, subjects cycled at the wattage corresponding to LT-20 W for 1 min and then workload increased 20 W every minute until volitional exhaustion to determine VO2max x On a separate occasion a self-paced, 20-k TT was completed. RESULTS: Mean values of blood lactate, HR and % HRmax, VO2 and % VO2max, and power output throughout the 20-k TT were greater (p<0.01) than those at LT. During the TT these cyclists performed at an intensity well above LT (blood lactate=252.0+/-0.1%, HR=9.4+/-0.03%, %HRmax=9.2+/-0.15%, VO2=26.5+/-0.7%, %VO2max=17.2+/-0.08% and power out-put=14.8+/-0.14% above LT) for over 30 min. CONCLUSIONS: Therefore, while LT may be highly correlated to performance, it may not be representative of race pace for a cycling TT, and may be questionable as a benchmark used to prescribe training intensity for competitive TT-cycling. |
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Authors:
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R W Kenefick; C O Mattern; N V Mahood; T J Quinn |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: The Journal of sports medicine and physical fitness Volume: 42 ISSN: 0022-4707 ISO Abbreviation: J Sports Med Phys Fitness Publication Date: 2002 Dec |
Date Detail:
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Created Date: 2002-10-22 Completed Date: 2003-01-30 Revised Date: 2004-11-17 |
Medline Journal Info:
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Nlm Unique ID: 0376337 Medline TA: J Sports Med Phys Fitness Country: Italy |
Other Details:
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Languages: eng Pagination: 396-402 Citation Subset: IM |
Affiliation:
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University of New Hampshire, Department of Kinesiology, Exercise Physiology Laboratory, Durham, New Hampshire 03824, USA. rwk@hopper.unh.edu |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Anaerobic Threshold / physiology* Bicycling / physiology* Exercise / physiology Exercise Test Heart Rate / physiology Humans Lactic Acid / blood* Male Oxygen Consumption / physiology Physical Endurance / physiology* Task Performance and Analysis |
| Chemical | |
Reg. No./Substance:
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50-21-5/Lactic Acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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