title: The use of energy drinks in sport: perceived ergogenicity and side effects in male and female athletes.
abstract: The use of caffeine containing energy drinks has dramatically increased in the last few years, especially in the sport context because of its reported ergogenic effect. The ingestion of low to moderate doses of caffeinated energy drinks has been associated with adverse side effects such as insomnia or increased nervousness. The aim of the present study was to assess psycho-physiological changes and the prevalence of side effects resulting from the ingestion of 3 mg caffeine/kg body mass in the form of an energy drink. In a double-blind and placebo controlled experimental design, ninety experienced and low-caffeine-consuming athletes (fifty-three male and thirty-seven female) in two different sessions were provided with an energy drink that contained 3 mg/kg of caffeine or the same decaffeinated energy drink (placebo; 0 mg/kg). At 60 min after the ingestion of the energy drink, participants completed a training session. The effects of ingestion of these beverages on psycho-physiological variables during exercise and the rate of adverse side effects were measured using questionnaires. The caffeinated energy drink increased self-perceived muscle power during exercise compared with the placebo beverage (6·41 (sd 1·7) v. 5·66 (sd 1·51); P= 0·001). Moreover, the energy drink produced a higher prevalence of side effects such as insomnia (31·2 v. 10·4 %; P< 0·001), nervousness (13·2 v. 0 %; P= 0·002) and activeness (16·9 v. 3·9 %; P= 0·007) than the placebo energy drink. There were no sex differences in the incidence of side effects (P>0·05). The ingestion of an energy drink with 3 mg/kg of caffeine increased the prevalence of side effects. The presence of these side effects was similar between male and female participants.
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Salinero
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Lara
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Abian-Vicen
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gonzalez-Millán
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Areces
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: César
authors.initials: C
authors.lastname: Gallo-Salazar
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Ruiz-Vicente
authors.affiliation: Exercise Physiology Laboratory, Camilo José Cela University, Castillo de Alarcon,49 Villafranca del Castillo,Madrid28692,Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Del Coso
mesh_terms: D000328:Adult; D001007:Anxiety / Q000139:chemically induced; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology / Q000523:psychology; D002110:Caffeine / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D061215:Energy Drinks / Q000009:adverse effects*; D015444:Exercise / Q000502:physiology / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength; D010465:Perception / Q000187:drug effects; D058573:Performance-Enhancing Substances; D010919:Placebos; D012737:Sex Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000139:chemically induced; D013177:Sports; D055815:Young Adult
chemical_list: D058573:Performance-Enhancing Substances; D010919:Placebos; D002110:Caffeine