The placebo and nocebo effects on peak minute power during incremental arm crank ergometry

Lindsay Bottoms,Richard Buscombe,Andrew Nicholettos

doi:10.1080/17461391.2013.822564

Abstract

This investigation aimed to explore the effects of inert sugar-free drinks described as either ‘performance enhancing’ (placebo) or ‘fatigue inducing’ (nocebo) on peak minute power (PMP;W) during incremental arm crank ergometry (ACE). Twelve healthy, non-specifically trained individuals volunteered to take part. A single-blind randomised controlled trial with repeated measures was used to assess for differences in PMP;W, oxygen uptake, heart rate (HR), minute ventilation, respiratory exchange ratio (RER) and subjective reports of local ratings of perceived exertion (LRPE) and central ratings of perceived exertion (CRPE), between three separate, but identical ACE tests. Participants were required to drink either 500 ml of a ‘sports performance’ drink (placebo), a ‘fatigue-inducing’ drink (nocebo) or water prior to exercise. The placebo caused a significant increase in PMP;W, and a significant decrease in LRPE compared to the nocebo (p=0.01; p=0.001) and water trials (p=0.01). No significant differences in PMP;W between the nocebo and water were found. However, the nocebo drink did cause a significant increase in LRPE (p=0.01). These results suggest that the time has come to broaden our understanding of the placebo and nocebo effects and their potential to impact sports performance.

Highlights

The placebo effect in sport has only become a subject of regular research enquiry in the last 10 to 15 years
(Table 1), whereas only 5 out of 12 participants produced a lower peak minute power (PMP);W on the nocebo trial compared to the water trial
Post - hoc analyses demonstrated a significant increase in PMP;W using the placebo compared to water (p= .013), and the nocebo (p= .044)

Summary

Introduction

The placebo effect in sport has only become a subject of regular research enquiry in the last 10 to 15 years. Kalasountas et al (2007) reported significant decreases in performance when subjects were told that their improvements in weightlifting were the result of a sham anabolic steroid Such a suggestion assumes the nocebo effect is reversing a positive outcome, which may underestimate its true potential to negatively impact performance if studied in isolation. Testing this hypothesis, Beedie, Coleman and Foad (2007) observed a trend towards reduced speed in consecutive sprint trials in a group that held a negative belief about an inert substance. It was hypothesised that the sports performance and fatigue inducing drink would significantly increase and decrease PMP;W respectively, compared to a comparison test using water

Methods

Participants

Procedures:

Results

Discussion