Document Detail


Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot & humid climate.
MedLine Citation:
PMID:  20693587     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND & OBJECTIVES: Athletes in Malaysia need to perform in a hot and humid climate. Chronic supplementation of caffeine on endurance performance have been studied extensively in different populations. However, concurrent research on the effects of acute supplementation of caffeine on cardiorespiratory responses during endurance exercise in the Malaysian context especially in a hot and humid environment is unavailable.
METHODS: Nine heat adapted recreational Malaysian male runners (aged: 25.4+/-6.9 yr) who were nonusers of caffeine (23.7+/-12.6 mg per day) were recruited in this placebo--controlled double--blind randomized study. Caffeine (5 mg per kg of body weight) or placebo was ingested in the form of a capsule one hour prior to the running exercise trial at 70 per cent of VO2max on a motorised treadmill in a heat-controlled laboratory (31 degrees C, 70% relative humidity). Subjects drank 3 ml of cool water per kg of body weight every 20 min during the running trials to avoid the adverse effects of dehydration. Heart rate, core body temperature and rate of perceived exertion (RPE) were recorded at intervals of 10 min, while oxygen consumption was measured at intervals of 20 min.
RESULTS: Running time to exhaustion was significantly (P<0.05) higher in the caffeine trial compared to the placebo trial. Heart rate, core body temperature, oxygen uptake and RPE did not show any significant variation between the trials but it increased significantly during exercise from their respective resting values in both trials (P<0.001).
INTERPRETATION & CONCLUSION: Our study showed that ingestion of 5 mg of caffeine per kg of body weight improved the endurance running performance but did not impose any significant effect on other individual cardiorespiratory parameters of heat-acclimated recreational runners in hot and humid conditions.
Authors:
Wong Chee Ping; Chen Chee Keong; Amit Bandyopadhyay
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Publication Detail:
Type:  Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Indian journal of medical research     Volume:  132     ISSN:  0971-5916     ISO Abbreviation:  Indian J. Med. Res.     Publication Date:  2010 Jul 
Date Detail:
Created Date:  2010-08-09     Completed Date:  2010-11-30     Revised Date:  2011-01-25    
Medline Journal Info:
Nlm Unique ID:  0374701     Medline TA:  Indian J Med Res     Country:  India    
Other Details:
Languages:  eng     Pagination:  36-41     Citation Subset:  IM    
Affiliation:
Sports Science Unit, School of Medical Sciences, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan Malaysia.
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MeSH Terms
Descriptor/Qualifier:
Adult
Body Composition
Body Mass Index
Body Temperature
Caffeine / pharmacology*
Diuresis / drug effects*
Double-Blind Method
Exercise / physiology*
Heart Rate / drug effects
Humans
Malaysia
Male
Muscle, Skeletal / drug effects*
Oxygen Consumption / drug effects*,  physiology
Performance-Enhancing Substances / pharmacology*
Chemical
Reg. No./Substance:
0/Performance-Enhancing Substances; 58-08-2/Caffeine
Comments/Corrections
Comment In:
Indian J Med Res. 2010 Jul;132:11-3   [PMID:  20693584 ]

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


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