Effects of Acute Caffeine Ingestion on Cognitive Performance before and after Repeated Small-Sided Games in Professional Soccer Players: A Placebo-Controlled, Randomized Crossover Trial

Abstract

Soccer is a team sport that requires players to process a significant amount of information quickly and respond with both speed and accuracy to the ever-changing demands of the game. As such, success in soccer depends not only on physical attributes but also on cognitive abilities such as perception and decision-making. The aim of the current study was to investigate the acute effects of caffeine ingestion on Stroop test performance before and after repeated small-sided games (SSG) in professional soccer players. Twelve professional male soccer players (29 ± 4.1 years; 78.1 ± 7.7 kg body mass) participated in this study. A randomized crossover double-blind placebo-controlled trial was used. Caffeine (5 mg.kg−1) or a placebo was ingested 45 min before a protocol consisting of five 5 min SSG with 1 min rest intervals. A computerized version of the colour Stroop test was completed immediately before and after the exercise protocol. During the Stroop test, words appeared on the computer screen in three different ways: (i) neutral words (neutral condition); (ii) correspondent colour (i.e., “red” painted in red; congruent condition), or; (iii) different colour (i.e., “red” painted in green; incongruent condition). The incongruent condition aimed to cause the interference effect, as the colour and the word did not match. Ratings of perceived exertion (RPE) were assessed after each SSG. RPE increased during the five sets of the SSG protocol (p < 0.001), without differences between the caffeine and placebo trials. The soccer-specific exercise protocol promoted a faster response during the Stroop test (two-way ANOVA main effect for SSG protocol: p < 0.05), with no differences in accuracy (p > 0.05). Caffeine ingestion resulted in slower reaction time during the Stroop test during the congruent and neutral trials but not during the incongruent trial (two-way ANOVA main effect for supplementation: p = 0.009, p = 0.045, and p = 0.071, respectively). Accuracy was lower in the caffeine trial in congruent and incongruent trials (p < 0.05 caffeine vs. placebo both on the pre- and post-SSG protocol). In conclusion, a soccer-specific exercise protocol improved the Stroop test performance in professional soccer players, but acute caffeine ingestion (5 mg.kg−1) was detrimental.

Effects of Various Caffeine Doses on Cognitive Abilities in Female Athletes with Low Caffeine Consumption

“…However, these results contrast with those of other studies in which the same dosage of CAF did not significantly impact Stroop test performance in rested participants [ 54 , 55 ]. De Almeida et al [ 23 ] reported that a soccer-specific exercise protocol improved Stroop test performance in professional soccer players, but acute CAF ingestion (5 mg·kg −1 ) was detrimental. Moreover, Bougrine et al [ 21 ] and Ali et al [ 20 ] reported an increase in reaction time and selective attention after the administration of 6 mg·kg −1 of CAF to female athletes.…”

“…Furthermore, evidence suggests that a dosage of 5 mg·kg −1 of CAF can improve cognitive performance after an arm-based Wingate test [ 22 ]. However, interestingly, the acute intake of an identical dosage (5 mg·kg −1 ) of CAF might detrimentally affect the performance of professional soccer players, particularly in the computerized Stroop test [ 23 ]. A dose of 3 mg·kg −1 of CAF did not affect the multiobject tracking ability of active men [ 24 ].…”

Mapping the research trend in the Web of Science on small-sided games in soccer: a Bibliometric study between 2010-2023

“…En otro ámbito, la suplementación y los efectos de ella, han sido investigados por (de Almeida et al, 2023), donde en un formato de 3 VS 3 + portero en cada equipo, con un área de 36 metros X 27 metros y 5 min de duración, se dio la ingestión de soluciones de cafeína (5 mg.kg-1) o un placebo a los jugadores, siete días después, se repitió el protocolo de los SSG, totalizando dos sesiones experimentales con placebo o cafeína, hallando que la ingestión de de cafeína tuvo un impacto negativo en el rendimiento de los participantes (Glaister & Gissane, 2018), esto se vio reflejado en el test de Stroop, determinando el tiempo medio de respuesta (ms) y la precisión (% de respuestas correctas), en el cual se evalúa la interferencia producida por diferentes aspectos de una misma estimulación (Scarpina & Tagini, 2017). Por otro lado, otras propuestas concluyen que la cafeína influye en aspectos de las decisiones tácticas en el fútbol, dando lugar a menos errores ofensivos y defensivos, aunque puede ser perjudicial teniendo en cuenta otros elementos tácticos, sugiriendo más investigación acerca de la ingestión de cafeína sobre parámetros específicos de la toma de decisiones en el fútbol (de Almeida et al, 2022).…”