title: The acute effects of a caffeine-containing supplement on strength, muscular endurance, and anaerobic capabilities.
abstract: The purpose of this study was to examine the acute effects of a caffeine-containing supplement on upper- and lower-body strength and muscular endurance as well as anaerobic capabilities. Thirty-seven resistance-trained men (mean +/- SD, age: 21 +/- 2 years) volunteered to participate in this study. On the first laboratory visit, the subjects performed 2 Wingate Anaerobic Tests (WAnTs) to determine peak power (PP) and mean power (MP), as well as tests for 1 repetition maximum (1RM), dynamic constant external resistance strength, and muscular endurance (TOTV; total volume of weight lifted during an endurance test with 80% of the 1RM) on the bilateral leg extension (LE) and free-weight bench press (BP) exercises. Following a minimum of 48 hours of rest, the subjects returned to the laboratory for the second testing session and were randomly assigned to 1 of 2 groups: a supplement group (SUPP; n = 17), which ingested a caffeine-containing supplement, or a placebo group (PLAC; n = 20), which ingested a cellulose placebo. One hour after ingesting either the caffeine-containing supplement or the placebo, the subjects performed 2 WAnTs and were tested for 1RM strength and muscular endurance on the LE and BP exercises. The results indicated that there was a significant (p < 0.05) increase in BP 1RM for the SUPP group, but not for the PLAC group. The caffeine-containing supplement had no effect, however, on LE 1RM, LE TOTV, BP TOTV, PP, and MP. Thus, the caffeine-containing supplement may be an effective supplement for increasing upper-body strength and, therefore, could be useful for competitive and recreational athletes who perform resistance training.
authors.affiliation: Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68588, USA. tbeck@unlserve.unl.edu
authors.forename: Travis W
authors.initials: TW
authors.lastname: Beck
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Housh
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schmidt
authors.forename: Glen O
authors.initials: GO
authors.lastname: Johnson
authors.forename: Dona J
authors.initials: DJ
authors.lastname: Housh
authors.forename: Jared W
authors.initials: JW
authors.lastname: Coburn
authors.forename: Moh H
authors.initials: MH
authors.lastname: Malek
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000187:drug effects* / Q000502:physiology; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005080:Exercise Test; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000187:drug effects* / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D014891:Weight Lifting / Q000502:physiology
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine