"Because I know it will!": placebo effects of an ergogenic aid on athletic performance

J Sport Exerc Psychol. 2007 Jun;29(3):382-94. doi: 10.1123/jsep.29.3.382.


In the perpetual quest for better performance, athletes are using an increasingly diverse range of ergogenic aids. Some are permitted; however, this "drug" use is often seen as an ethically questionable behavior. A variety of research suggests that much of the impact of such aids may be due to expectancy-the belief that the substance will aid performance. It would be useful to demonstrate this to athletes considering such usage, especially as a pillar of antidrug education. Accordingly, this investigation used sodium bicarbonate and placebo additives in a double disassociation design, with athletes completing a series of 1,000-m time trials. Results showed that believing one had taken the substance resulted in times almost as fast as those associated with consuming the drug itself. In contrast, taking the drug without knowledge yielded no significant performance increment. Results are discussed against the backdrop of applying expectancy effects in high-performance sport, including dissuading athletes from using illegal aids.

MeSH terms

  • Adolescent
  • Adult
  • Culture*
  • Doping in Sports / psychology*
  • Double-Blind Method
  • Female
  • Heart Rate / drug effects
  • Heart Rate / physiology
  • Humans
  • Lactic Acid / blood
  • Male
  • Physical Endurance / drug effects
  • Placebo Effect
  • Sodium Bicarbonate / administration & dosage*
  • Sports / psychology*


  • Lactic Acid
  • Sodium Bicarbonate