The Influence of Caffeine Expectancies on Sport, Exercise, and Cognitive Performance

Abstract

Caffeine (CAF) is widely consumed across sport and exercise for its reputed ergogenic properties, including central nervous stimulation and enhanced muscular force development. However, expectancy and the related psychological permutations that are associated with oral CAF ingestion are generally not considered in most experimental designs and these could be important in understanding if/how CAF elicits an ergogenic effect. The present paper reviews 17 intervention studies across sport, exercise, and cognitive performance. All explore CAF expectancies, in conjunction with/without CAF pharmacology. Thirteen out of 17 studies indicated expectancy effects of varying magnitudes across a range of exercise tasks and cognitive skills inclusive off but not limited to; endurance capacity, weightlifting performance, simple reaction time and memory. Factors, such as motivation, belief, and habitual CAF consumption habits influenced the response. In many instances, these effects were comparable to CAF pharmacology. Given these findings and the lack of consistency in the experimental design, future research acknowledging factors, such as habitual CAF consumption habits, habituated expectations, and the importance of subjective post-hoc analysis will help to advance knowledge within this area.

Translation and Validation of the Caffeine Expectancy Questionnaire in Brazil (CaffEQ-BR)

“…However, these results were not observed in physiological variables, such as heart rate and blood pressure [16], further reinforcing the notion that the expected effect of caffeine plays a subjective role in the belief around its consumption [16,17]. Regarding expectancy, factors such as motivation and belief can influence the ergogenic response of caffeine in adults [17]. Therefore, expectancies associated with caffeine use/outcome may play an important role in the development, maintenance, and reinforcement of its consumption patterns [12,18,19].…”

“…Positive expectation associated with caffeine ingestion appeared to drive this effect since individuals correctly believing that they had ingested caffeine improved to a greater extent than the average effect of caffeine [13,15]. However, these results were not observed in physiological variables, such as heart rate and blood pressure [16], further reinforcing the notion that the expected effect of caffeine plays a subjective role in the belief around its consumption [16,17]. Regarding expectancy, factors such as motivation and belief can influence the ergogenic response of caffeine in adults [17].…”

Effects of Expectancy on Cognitive Performance, Mood, and Psychophysiology in Healthy Adolescents and Their Parents in an Experimental Study

“…Concerning placebo effects on cognitive performance, recent studies have focused on the role of expectancies about the effectiveness of the intervention (post hoc subjective outcome). In some cases, rather the expectancies affect objective cognitive performance than the sole information of receiving an intervention (42)(43)(44). High prior expectations can increase post hoc expectancies about the intervention, yet they do not necessarily affect objective cognitive outcomes (45).…”

Is Coffee a Useful Source of Caffeine Preexercise?

“…Caffeine, and likely coffee, potentially exerts some of its ergogenic effects via expectancy and placebo (Shabir et al, 2018), such that when individuals believe they have consumed caffeine, and believe caffeine is ergogenic, their performance is often greater than if they believe they have not consumed caffeine (Saunders et al, 2017). As caffeine, ingested via capsules or coffee, may exert negative, performance-limiting side effects such as increased anxiety (Childs et al, 2008), the use of placebos to exert performance benefits in these cases may be advantageous, if not ethically challenging.…”