title: Acute ingestion of sugar-free red bull energy drink has no effect on upper body strength and muscular endurance in resistance trained men.
abstract: Consumption of energy drinks by both recreational and competitive athletes has increased dramatically in recent years. The primary ingredients in many energy drinks include caffeine (CAF) in various forms and taurine. The purpose of this randomized, double-blind, crossover study was to examine the effect of sugar-free (SF) Red Bull (RB) containing CAF and taurine to a CAF only drink and a SF CAF-free placebo (PL) on 1 repetition maximum (1RM) bench press (BP) and the volume load (VL; repetitions × kg at 70% 1RM) during one BP set to failure in experienced lifters. Seventeen college-age men randomly received the following: (A) 500 mL of SF-RB containing CAF (160 mg) and taurine (2000 mg); (B) 500 mL of a SF drink containing CAF only (160 mg); or (C) a SF CAF-free 500 mL PL drink 60 minutes before testing on 3 separate occasions. After a standard warm-up, the 1RM was determined for each subject and, after 5 minutes rest, they completed repetitions to failure at 70% of their 1RM to assess VL. Differences between trials for 1RM BP and the VL were identified using repeated measures analysis of variance (p < 0.05). The results indicated that neither SF-RB nor the CAF drink had any effect on 1RM BP (115.13 ± 16.19 kg and 114.87 ± 16.16 kg, respectively) or VL (1173.08 ± 170.66 kg and 1164.14 ± 147.03 kg, respectively) compared with PL (1RM = 114.07 ± 16.09 kg; VL = 1141.46 ± 193.41 kg). Although the CAF content in the energy drinks used in the present study was low (∼2.0 mg/kg), the finding of no effect of the CAF containing energy drinks for 1RM BP are in agreement with previous studies using intakes up to 6.0 mg/kg. These findings suggest that SF-RB has no effect on upper body 1RM strength or VL in resistance trained men.
authors.affiliation: Department of Exercise Science, Human Performance Research Laboratory, Creighton University, Omaha, Nebraska, USA. eckerson@creighton.edu
authors.forename: Joan M
authors.initials: JM
authors.lastname: Eckerson
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Bull
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Baechle
authors.forename: Chelsea A
authors.initials: CA
authors.lastname: Fischer
authors.forename: Daniel C
authors.initials: DC
authors.lastname: O'Brien
authors.forename: Geri A
authors.initials: GA
authors.lastname: Moore
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Yee
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Pulverenti
mesh_terms: D000328:Adult; D002110:Caffeine / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D061215:Energy Drinks; D005080:Exercise Test; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000187:drug effects*; D053580:Muscle Strength / Q000187:drug effects*; D010807:Physical Endurance / Q000187:drug effects*; D055070:Resistance Training; D013654:Taurine / Q000494:pharmacology; D055815:Young Adult
chemical_list: D013654:Taurine; D002110:Caffeine