ChrisBeedie

Chris Beedie
Honorary Professor in Cognition and Neuroscience in the School of Psychology, University of Kent, Canterbury, UK.

Citius, Altius, Fortius: How placebos make humans run faster

Placebo and nocebo effects have been widely reported in the sports science literature. Significant placebo induced improvement in performance can occur in the absence of significant increase in physiological stress (i.e., effort) (1); athletes can experience a dose:response placebo effect to different ‘doses’ of placebo (2), larger placebo effects are evident when athletes are led to believe they have been given banned drugs (3), athletes often perform below baseline when they correctly believe that they have ingested a placebo (2, 4), and athletes who intend to use a real sport supplement are more likely to respond to a placebo (5).

A number of neurobiological systems, notably opioid, endocannabinoid and dopamine, are theoretically implicated, but systematic neurobiological research into placebo effects in sports science is as yet not happening. However, given that the type of placebo treatment appears to mediate the magnitude of effects (e.g., small in caffeine and large in steroids), it is likely that in sport, as has been reported elsewhere, placebo mechanism mimic drug mechanisms.

Placebos in sport, as is the case elsewhere, are catalysed by positive cues. It would be reasonable to assume therefore that a placebo effect that improves sports performance is the result of expectation driven improvements in ‘positive’ variables such as energy availability, motivation, confidence or motor coordination. However, there are many negative cues in sport, anxiety, pain and fatigue notable amongst them. Importantly, athletes often report that placebo effects they have experienced are the result of reductions in these negative cues (1). It is also relevant that these cues each have a substantial subjective component.

Previously we proposed the concept of headroom, a ‘gap’ between an athlete’s current level of performance and what that athlete is ultimately capable of (6). We have speculated that the placebo effect operates in this headroom (6). Headroom is however by definition a deficit. Further, it is likely that this gap between current and optimum performance results at least in part from the subjective negative cues above; anxiety, pain and fatigue. The magnitude of any headroom might therefore be a function of subjective negative cues, therefore theoretically, also a function of nocebo effects. In this context, it is possible that in sport, a placebo treatment works by reducing the magnitude of nocebo effects.

 

References 

  1. Beedie C, Foad A. The placebo effect in sports performance: a brief review. Sports Med. 2009;39(4):313-29.
  2. Beedie C, Stuart E, Coleman D, Foad A. Placebo effects of caffeine on cycling performance. Med Sci Sports Exerc. 2006;38(12):2159-64.
  3. Hurst P, Schiphof-Godart l, Raglin J, Coleman D, Lane A, Foad A, et al. Placebo effects on Sports Performance: A Systematic Review. European Journal of Sport Science. In Press.
  4. Foad AJ, Beedie CJ, Coleman DA. Pharmacological and psychological effects of caffeine ingestion in 40-km cycling performance. Med Sci Sports Exerc. 2008;40(1):158-65.
  5. Hurst P, Foad AJ, Coleman DA, Beedie C. Athletes Intending to Use Sports Supplements Are More Likely to Respond to a Placebo. Med Sci Sports Exerc. 2017;40(9):1877-83.
  6. Beedie C, Whyte G, Lane AM, Cohen E, Raglin J, Hurst P, et al. ‘Caution, this treatment is a placebo. It might work, but it might not’: why emerging mechanistic evidence for placebo effects does not legitimise complementary and alternative medicines in sport. British Journal of Sports Medicine. 2017;52:817-8.

 

Biosketch

Chris Beedie is Honorary Professor in Cognition and Neuroscience in the School of Psychology at the University of Kent, Canterbury, UK. He is also Science Director of CHX Performance, based in Chamonix, France and London, England. He has published over 100 papers and chapters on placebo effects and related psychological/physiological self-regulatory systems such as emotion and self-control, many of these in the context of sports performance. As an ex-international endurance athlete he has first-hand experience of the role of expectation and belief in performance, and in his applied work helps high performance athletes and corporate executives understand these mind-body effects.