title: Effect of sugar-free Red Bull energy drink on high-intensity run time-to-exhaustion in young adults.
abstract: Consuming sugar-free Red Bull energy drink before exercise has become increasingly popular among exercising individuals. The main purported active ingredient in sugar-free Red Bull is caffeine, which has been shown to increase aerobic exercise performance. The purpose of this study was to determine the effects of sugar-free Red Bull energy drink on high-intensity run time-to-exhaustion in young adults. Physically active university students (n = 17, 9 men, 8 woman; 21 +/- 4 years, 73.4 +/- 3.1 kg, 175.1 +/- 3.2 cm) participated in a double-blind, crossover, repeated-measures study where they were randomized to supplement with sugar-free Red Bull (2 mg x kg(-1) body mass caffeine or approximately 147 mg caffeine; 4 kcal/250 mL) and noncaffeinated, sugar-free placebo (lemon-lime flavored soft drink, tonic water, lime juice; 4 kcal/250 mL) separated by 7 days. Exercise capacity was assessed by a run time-to-exhaustion test at 80% Vo2max, perceived exertion was assessed immediately after exercise, and blood lactate was measured before and after exercise. There were no differences in run time-to-exhaustion (Red Bull: 12.6 +/- 3.8 minutes, placebo: 11.8 +/- 3.4 minutes), perceived exertion (Red Bull: 17.1 +/- 2.0, placebo: 16.6 +/- 1.8), or blood lactate between groups. In conclusion, sugar-free Red Bull energy drink did not influence high-intensity run time-to-exhaustion in young adults.
authors.affiliation: Faculty of Kinesiology and Health Studies, University of Regina, Regina, Saskatchewan, Canada. darren.candow@uregina.ca
authors.forename: Darren G
authors.initials: DG
authors.lastname: Candow
authors.forename: Amanda K
authors.initials: AK
authors.lastname: Kleisinger
authors.forename: Stephanie
authors.initials: S
authors.lastname: Grenier
authors.forename: Kim D
authors.initials: KD
authors.lastname: Dorsch
mesh_terms: D000704:Analysis of Variance; D001628:Beverages; D002110:Caffeine / Q000494:pharmacology*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D005082:Physical Exertion; D010919:Placebos; D012420:Running / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D007773:Lactates; D010919:Placebos; D002110:Caffeine