Caffeine Mouth Rinsing at Different Doses in Female Team-Sport Athletes: A Randomized, Double-Blind, Placebo-Controlled Trial

Caffeine Mouth Rinsing at Different Doses Does Not Enhance Anaerobic Sprint Performance in Female Team-Sport Athletes: A Randomized, Double-Blind, Placebo-Controlled Trial

Objective:

To evaluate the effects of different caffeine mouth rinse concentrations (1%, 2%, and 3%) on Running Anaerobic Sprint Test (RAST) performance in female team-sport athletes.

Main Questions:

1. Do caffeine mouth rinses improve RAST performance in female team-sport athletes?
2. Do different caffeine mouth rinse concentrations affect ratings of perceived exertion (RPE)?

Method:

Thirteen trained female football and handball players (23.0 ± 4.5 years) completed four randomized, double-blind, crossover conditions (1%, 2%, and 3% caffeine mouth rinses, and placebo). Each trial involved six 35 m sprints separated by 10 s of rest. RPE was recorded immediately after each session.

Objective:

To evaluate the acute effects of different caffeine mouth rinse concentrations (1%, 2%, and 3%) on anaerobic sprint performance and perceived exertion in trained female team-sport athletes. The study sought to determine whether this non-ingestive ergogenic strategy could enhance high-intensity running performance and reduce effort perception.

Main Questions:

1. Do different caffeine mouth rinse concentrations improve Running Anaerobic Sprint Test (RAST) performance in trained female team-sport athletes?
2. Do caffeine mouth rinses at varying concentrations influence ratings of perceived exertion (RPE) compared with placebo?

Is there an optimal caffeine concentration that balances potential performance benefits with reduced perceived exertion?

Method:

Thirteen trained female athletes (mean age 23.0 ± 4.5 years) competing in football and handball participated in a randomized, double-blind, placebo-controlled, crossover trial. Each athlete completed four experimental conditions: placebo, 1% caffeine mouth rinse, 2% caffeine mouth rinse, and 3% caffeine mouth rinse. In each session, participants performed a Running Anaerobic Sprint Test (RAST) consisting of six maximal 35 m sprints separated by 10 seconds of passive recovery. The RPE was assessed immediately after each test using a 1-10 scale.

Inclusion Criteria

• Female team sports athletes aged between 18 and 35 years.
• Currently engaged in team sports.
• Non-smoker.

Exclusion Criteria

• Participants were excluded if they met any of the following conditions.
• Presence of a musculoskeletal injury within the six months prior to the study.
• Current smoker.
• Use of nutritional supplements or ergogenic aids that could influence sprint running performance (e.g., beta-alanine, creatine).
• Use of oral contraceptives.
• Known allergy to caffeine.
• Failure to meet the training requirement of at least six hours of team-based practice, a minimum of three days per week, over the past year.