THE ACUTE EFFECTS OF A CAFFEINE-CONTAINING SUPPLEMENT ON STRENGTH,MUSCULAR ENDURANCE, AND ANAEROBIC CAPABILITIES.
BECK, TRAVIS W. 1; HOUSH, TERRY J. 1; SCHMIDT, RICHARD J. 1; JOHNSON, GLEN O. 1; HOUSH, DONA J. 2; COBURN, JARED W. 1; MALEK, MOH H. 1
Journal of Strength & Conditioning Research.
20(3):506-510, August 2006.
(Format: HTML, PDF)
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.
(C) 2006 National Strength and Conditioning Association