Caffeine Vs. Carbohydrate Mouth Rinsing in Soccer

Not Applicable

Completed

• Conditions: Performance; Soccer; Cognitive Function; Caffeine and Carbohydrate; Technical Skill

• Registration Number: NCT06881316
• Lead Sponsor: Tokat Gaziosmanpasa University

Brief Summary

The present study evaluated the influence of carbohydrate mouth-rinsing (CHO-MR), caffeine mouth-rinsing (CAF-MR), and control-substance mouth rinses on Loughborough soccer passing test (LSPT) performance. The study participants were involved in a randomized, double-blind, repeated-measures design that employed four sessions (familiarization, CHOMR, CAFMR, and CONT) over ten days at a testing facility. Participants took part in six test sessions 72 hours apart. In the CHO group, 6% w/v glucose solution was used. In the CAFF group, 6% w/v glucose solution was used. CONT group, only exercise was performed without any condition.

Detailed Description

Participants were involved in a randomized, double-blind, repeated-measures design that employed four sessions (familiarization, LSPTCHO, LSPTCAFF, and LSPTCONT) over ten days at a testing facility. The initial session was an orientation, allowing participants to acclimate to the LSPT protocol and provide written informed consent. This session used water as a mouth rinse. Anthropometric data were also collected. Before the LSPT, participants completed 15-minute standardized warm-up sections, including jogging, sprinting, and integrating soccer-specific actions. The participants were asked to complete the LSPT at any time. During the tests, participants were blinded to the test scores. The following three sessions were test trials conducted between 15.00 h and 17.00 h at 32°C and 40% humidity. The participants performed the LSPT 72 h apart, LSPTCHO (6% w/v glucose solution), LSPTCAFF (1.2% w/v caffeine solution), and LSPTCONT conditions. Caffeine and CHO solutions were prepared in an equivalent saccharin base to ensure indistinguishability within the Falcon Sterile Tube and agitated for 30 seconds on a vortex mixer. Participants were instructed to avoid intense activity 24 hours before testing, observe a 2-hour fast before sessions, and abstain from caffeinated products on test days. All the test sessions were performed at 32°C and 40% humidity.

Study Timeline

• Study Start: 2025-02-10
• Primary Completion: 2025-02-25
• Study Completion: 2025-02-26
• Status Verified: 2025-03
• Study First Submitted: 2025-03-05
• Study First Submitted QC: 2025-03-10
• Last Update Submitted: 2025-03-10
• Study First Posted: 2025-03-18
• Last Update Posted: 2025-03-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 20

Inclusion Criteria

• Being healthy
• Male soccer players
• Willing to maintain the intervention for all sessions

Exclusion Criteria

• Being under 14 years old
• Having a chronic disease
• Contraindication for caffeine mouth-rinsing (CAF-MR)
• Contraindication for carbohydrate mouth-rinsing (CHO-MR)
• Contraindications for exercise

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Psychophysiological Responses-Heart Rate	From baseline to the end of treatment at 2 weeks	Participants used a Polar H10 heart rate (HR) transmitter synchronized with a Polar V800 watch to track the HR throughout the session. Participants' heart rate mean, heart rate peak and heart rate percentage were recorded.
Psychophysiological Responses-Rating of Perceived Exertion	From baseline to the end of treatment at 2 weeks	Exercise intensity in all test sessions was quantified using the rating of perceived exertion (RPE), which employs a category ratio scale ranging from 6 to 20. This scale has recently been applied in sports psychology to assess effort related to emotions and performance during competitive events.
Psychophysiological Responses-Enjoyment-Brunel mood of states	From baseline to the end of treatment at 2 weeks	all participants completed the exercise enjoyment scale (EES), which comprises eight items rated on a 1-7 Likert scale. This scale has been validated to measure enjoyment in Turkish adolescents and adults. To assess subjective mental fatigue levels, participants were instructed to indicate their degree of mental fatigue on a Visual Analog Scale (VAS).
Loughborough Soccer Passing Test (LSPT)	From baseline to the end of treatment at 2 weeks	Participants were informed that the LSPT was a timed performance assessment and instructed to complete it as expeditiously as possible while minimizing penalties. The LSPT comprises 16 passes: eight short passes to red and white targets 3.5m from the passing zone and eight slightly longer passes to green and blue targets 4m away. Targets were constructed by affixing colored cards (0.3 x 0.6m) to the center of standard gymnasium benches, with a vertical aluminum strip (0.1 x 0.15m) fixed to the target's center for auditory feedback on successful passes. Four randomized passing sequences were generated. An examiner announces that the subsequent target color is released immediately after the previous pass. A stopwatch measured the test duration, commencing when the participant moved the ball into the passing zone and concluding when the final pass contacted the target area.

Secondary Outcome Measures

Name	Time	Method
Anthropometric Measurements 1	Baseline	Before breakfast, participants had their weight (kg) measured using a body composition analyser (BC-418MA, Tanita Corp., Tokyo, Japan). This device utilises bioelectrical impedance technology using multiple frequencies (ranging from 1 kHz to 50 kHz) to comprehensively assess body composition parameters.

Trial Locations

Locations (1)

Tokat Gaziosmanpasa Universty; 🇹🇷 Tokat, Turkey