title: Positive and negative placebo effects resulting from the deceptive administration of an ergogenic aid.
abstract: The article describes a study examining placebo effects associated with the administration of a hypothetical ergogenic aid in sport. Forty-two team-sport athletes were randomly assigned to 2 groups. All subjects completed 3 x 30-m baseline sprint trials after which they were administered what was described to them as an ergogenic aid but was in fact 200 mg of cornstarch in a gelatin capsule. Group 1 was provided with positive information about the likely effects on performance of the substance, whereas Group 2 was provided with negative information about the same substance. The sprint protocol was repeated 20 min later. Although for Group 1 mean speed did not differ significantly between baseline and experimental trials, a significant linear trend of greater speed with successive experimental trials suggested that positive belief exerted a positive effect on performance (P < 0.01). Group 2 ran 1.57% slower than at baseline (P < 0.01, 95% confidence intervals 0.32-2.82%), suggesting that negative belief exerted a negative effect on performance. Collectively, data suggest that subjects' belief in the efficacy or otherwise of a placebo treatment might significantly influence findings in experimental research.
authors: Department of Sport Science, Tourism, and Leisure, Canterbury Christ Church University, Canterbury, UK.
authors: Christopher J
authors: CJ
authors: Beedie
authors: Damian A
authors: DA
authors: Coleman
authors: Abigail J
authors: AJ
authors: Foad
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D015990:Placebo Effect; D012420:Running / Q000502:physiology* / Q000523:psychology*; D013647:Task Performance and Analysis