All in the mind? Pain, placebo effect, and ergogenic effect of caffeine in sports performance

Abstract

Abstract:The ergogenic effects of caffeine on performance are well documented. These effects are more evident in endurance and short-duration, sustained-effort events than in interactive or stop-go sports. Experimentally-induced placebo effects of caffeine on sports performance have also been observed in a number of recent studies. In the present paper it is argued that, given the nature of the sports in which caffeine effects are observed, the well documented hypoalgesic effects of caffeine, and the fact that pain is highly placebo-responsive, a reduction in perceived pain might be the common factor in both the biologic and placebo ergogenic effects of caffeine on sports performance. This idea is supported by evidence from medicine that suggests placebo effects are often associated with mechanisms similar or identical to those of the substance the subject believes they have ingested. Research findings from both biomedicine and sports medicine that attest to the interaction of biologic and psychologic factors in caffeine and pain responses are briefly reviewed. In conclusion, it is recommended that researchers investigate the pain hypothesis. Furthermore, researchers should consider psychosocial factors that might modulate the pain response as variables of interest in future caffeine and performance research.

Acute Effects of Caffeine on Strength Performance in Trained and Untrained Individuals

“…As mentioned, this study was the first to investigate the effect of a caffeine placebo on 1 RM strength. However, in comparison to research obtained measuring muscular endurance [31][32][33] these findings did not support those previously published.…”

“…In terms of placebo ingestion, this study was the first to investigate the effect of a caffeine placebo on 1 RM strength performance. Results found do however coincide with those previous reported in muscular endurance [31][32][33].…”

“…Therefore, the hypothesis that placebo would produce a similar response to caffeine was met and supports previous research into caffeine placebos [28,31,32]. Muscle activation and force production did not significantly increase in either trained or untrained individuals supporting some previously published research [6,29] and contradicting others [27,28].…”

“…Enhanced muscular work output [33] and reports of caffeinerelated symptoms post placebo ingestion have been shown [31]. In addition, improved repetitions to failure and reduced RPE [32] have also been documented.…”

“…Interestingly caffeine placebos have been shown to significantly increase the performance of both endurance and muscular endurance based tasks, often to a similar degree to real caffeine supplements [31][32][33]. Enhanced muscular work output [33] and reports of caffeinerelated symptoms post placebo ingestion have been shown [31].…”