Carbohydrate Mouth Rinse (Small-Sided Soccer Games)

The present study evaluated the influence of carbohydrate mouth-rinsing (CHO- MR) and placebo (PLA) conditions on the psychophysiological responses, kinematic profiles, and technical performance of young male soccer players in 4-Small sided games (SSGs). The study participants were involved in a randomized, double-blind, repeated-measures design that employed 3 sessions (familiarization, CHOMR and PLA) over fifteen days at a testing facility. Participants took part in two test sessions one week apart. CHO solution was a maltodextrin-based mixture containing 6.4% maltodextrin (Protein Ocean, Türkiye). The PLA solution consisted of pure water. Both solutions were made indistinguishable by incorporating 50 mg of a non-calorific artificial sweetener and 50 mg og sucralose (Fibrelle, Türkiye). A 25-ml bolus of 6.4% maltodextrin solution was utilized in a pre-weighed plastic cup, with sucralose water tested as PLA for each rinse solution.

The current study used a double-blind, randomized, and counterbalanced crossover design to compare the effects of CHOMR or PLA on psychophysiological, kinematic responses and technical actions during 4-a-side SSGs. The study intervention programs lasted the same time of the day during separate training sessions in the in-season to avoid various chronobiological factors. The average temperature was 30 °C, with a relative humidity of 35% of the baseline assessments. Second assessments were recorded that the average temperature was 31 °C with a 35% relative humidity. Before the SSGs sessions, anthropometric characteristics were assessed. Players also completed the Yo-Yo Intermittent Recovery Test level 1 (YYIRTL-1) to balance the groups and equally distribute players among SSGs teams based on maximal oxygen uptake ( 2max). The order of different SSGs (CHOMR or PLA) and solutions (MR or PLA) was determined by randomization (www.randomization.com). Each SSGs was separated at least one week apart to minimize the potential negative impact of physical and psychological fatigue on game performance. Continuous monitoring and recording of the heart rate (HR), rating of perceived exertion (RPE), enjoyment and mental fatigue (MF), kinematic responses, and technical actions were conducted during all SSGs. Mood responses were assessed before and after each SSGs. UEFA A licenced strength and conditioning coaches consistently implemented all SSGs sessions on an artificial soccer pitch with verbal coach encouragement.