Document Detail


The effects of caffeine ingestion on time trial cycling performance.
MedLine Citation:
PMID:  18974717     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
AIM: The purpose of this work was to determine the effects of caffeine ingestion on cycling time trial (TT) performance in well trained male subjects. METHODS: Eight males, with the following physical characteristics (Mean +/- SD) age 30.2+/-10.1 years, height 180.3+/-7.1 cm, mass 70.4+/-5.1 kg, VO2max 63.6+/-4.4 mL.kg(-1).min(-1) undertook three 1 h TT performances on a VelotronPro cycle ergometer, in a double blind, random fashion. The trials were Control (C), Placebo (Pl) and Caffeine (CAF). The CAF and Pl were given 60 min prior to exercise in a dose of 6 mg.kg(-1) body mass. Prior to ingestion, 60 min post ingestion, and at the end of the TT, subjects gave 10 mL of venous blood which was analysed for lactate, glucose, and free fatty acids. Expired air was collected throughout each test by indirect calorimetry. RESULTS: The cyclists rode significantly further in CAF trial (28.11+/-1.32 km) than they did in the C (26.69+/-1.5 km, P < 0.03) or Pl (27.0+/-1.5 km, P < 0.03) trials. No significant differences were seen between C and Pl trials (P > 0.88). No differences between C and Pl were seen in heart rate data throughout the TT (p > 0.05). The free fatty acid (FFA) concentrations were significantly higher in the CAF trials both post ingestion (P < 0.005) and post exercise (P < 0.0001) than either C or Pl trials. CONCLUSION: We concluded that performance was improved possibly based upon a greater reliance on fat metabolism, as indicated by increased FFA and a lower respiratory exchange ratio (RER).
Authors:
L R Mc Naughton; R J Lovell; J C Siegler; A W Midgley; M Sandstrom; D J Bentley
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Publication Detail:
Type:  Clinical Trial; Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  The Journal of sports medicine and physical fitness     Volume:  48     ISSN:  0022-4707     ISO Abbreviation:  J Sports Med Phys Fitness     Publication Date:  2008 Sep 
Date Detail:
Created Date:  2008-10-31     Completed Date:  2008-12-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0376337     Medline TA:  J Sports Med Phys Fitness     Country:  Italy    
Other Details:
Languages:  eng     Pagination:  320-5     Citation Subset:  IM    
Affiliation:
Applied Physiology Laboratory, University of Hull, Hull, UK. l.mcnaughton@hull.ac.uk
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / physiology*
Adult
Bicycling / physiology*
Body Mass Index
Caffeine / pharmacology*,  therapeutic use
Calorimetry / instrumentation
Ergometry / instrumentation
Exercise Test
Exercise Tolerance / drug effects
Fatty Acids, Nonesterified*
Heart Rate / drug effects*
Humans
Male
Oxygen Consumption / drug effects
Physical Fitness / physiology*
Time
Young Adult
Chemical
Reg. No./Substance:
0/Fatty Acids, Nonesterified; 58-08-2/Caffeine

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


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