Document Detail


Effects of ephedrine, caffeine, and their combination on muscular endurance.
MedLine Citation:
PMID:  12783047     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: The purpose of this study was to investigate the effects of ingesting caffeine (C), ephedrine (E), and their combination on muscular endurance, using a double-blind, repeated measures design. METHODS: Ninety minutes after ingesting either C (4 mg x kg-1), E (0.8 mg x kg-1), a combination of C+E, or a placebo (P), 13 male subjects performed a weight-training circuit consisting of three supersets (SS), each SS consisting of leg press (at 80% of 1 RM to exhaustion) followed by bench press (at 70% 1-RM to exhaustion); 2 min of rest intervened between SS. RESULTS: The trials involving ephedrine ingestion (C+E and E), when compared with the nonephedrine trials (C and P), caused significant increases (P < 0.05) in the mean number of repetitions completed for both the leg-press and bench-press exercises but only during the first SS. During that first set, the mean number (+/-SD) of repetitions for leg press was 19 +/- 8, 16 +/- 7, 14 +/- 6, and 13 +/- 5 for the C+E, E, C, and P trials, respectively. The mean numbers of repetitions for the first set of bench-press exercise were 14 +/- 3, 13 +/- 3, 12 +/- 3, and 12 +/- 3 for the C+E, E, C, and P trials, respectively. As a result, the total weight lifted during all three sets was greater for the trials involving ephedrine ingestion. Systolic blood pressure before exercise was significantly increased with both ephedrine treatment trials when compared with the other trials (C+E = 156 +/- 29 mm Hg; E = 150 +/- 14; C = 141 +/- 16; P = 138 +/- 14). CONCLUSION: It was concluded that acute ingestion of C+E and E increases muscular endurance during the first set of traditional resistance-training exercise. The performance enhancement was attributed primarily to the effects of E; there was no additive effect of C.
Authors:
Ira Jacobs; Harley Pasternak; Douglas G Bell
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Publication Detail:
Type:  Clinical Trial; Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  Medicine and science in sports and exercise     Volume:  35     ISSN:  0195-9131     ISO Abbreviation:  Med Sci Sports Exerc     Publication Date:  2003 Jun 
Date Detail:
Created Date:  2003-06-03     Completed Date:  2003-09-04     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  8005433     Medline TA:  Med Sci Sports Exerc     Country:  United States    
Other Details:
Languages:  eng     Pagination:  987-94     Citation Subset:  IM; S    
Affiliation:
Defence R&D Canada-Toronto, Canada. Ira.Jacobs@drdc-rddc.gc.ca
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MeSH Terms
Descriptor/Qualifier:
Adolescent
Adult
Caffeine / administration & dosage,  pharmacology*
Central Nervous System Stimulants / administration & dosage,  pharmacology*
Double-Blind Method
Drug Interactions
Ephedrine / administration & dosage,  pharmacology*
Humans
Male
Muscle, Skeletal / drug effects,  physiology
Physical Endurance / drug effects*
Weight Lifting / physiology
Chemical
Reg. No./Substance:
0/Central Nervous System Stimulants; 299-42-3/Ephedrine; 58-08-2/Caffeine

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


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