Investigating the impact of exercise self-efficacy on the placebo effect in sport

The impact that exercise self-efficacy has on the effects of a placebo on athletes’ cardiovascular endurance was investigated in this study. Self-efficacy – one’s belief in their ability, plays a significant role in an individual’s performance. The placebo effect is characterised by the erroneous belief in a physically ineffective supplement. The interaction between these variables was explored. Participants were males between 18 and 59 years old (N = 55). The study employed an experimental design whereby athletes completed fitness tests with repeated measures after being split into low and high self-efficacy groups. An exercise self-efficacy scale and the multi-stage fitness test (a.k.a. the bleep test) were used. Fitness test scores were significantly greater in the placebo condition than in the non-placebo condition. A significant difference was found whereby those with higher task-efficacy achieved higher fitness test scores. There were no significant differences found between the fitness test scores of those with low and high coping-efficacy or scheduling-efficacy. Lastly, there were no interactions found between any of the self-efficacy categories and the placebo effect. The implications of the findings regarding task-efficacy, the placebo effect and their lack of interaction were discussed. The strengths, limitations and suggestions for future research in the area of exercise self-efficacy were discussed.