Menthol Mouth Rinsing and Performance Responses of Elite Football Referees in the Heat

NCT ID: NCT05632692

Last Updated: 2022-11-30

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-04-10
• Study Completion Date: 2023-06-01

Brief Summary

Ten male football referees will be recruited to perform two intermittent football protocols , separated by at least 7 days (wash-out period). After passing the eligibility criteria, the participants will be randomly assigned, according to a computer-generated allocation schedule, to 1 of 2 beverages sequences: (1) intervention - menthol solution 0.01% (room temperature) and (2) placebo - noncaloric berry-flavoured solution (room temperature). The participants will be provided with one of the 2 beverages before warm-up (pre-cooling) and at the half-time (per-cooling). The trials will follow a randomised counterbalanced crossover design, blinded to the participants, and will take place in indoor facilities, where WBGT exceed 30◦C, at the same time of the day, to control for circadian variations. Each trial involves an exercise protocol (SAFT-90), lasting 90 minutes, separated into two 45-minute parts. The first half will be preceded by a warm-up and the second half by a 15-minute break.

The results of this study are expected to determine whether mouth rinsing a menthol solution, before a football exercise protocol performed in the heat, will help to alleviate physiological strain and improve performance parameters, comparing to a non-cooling strategy, in elite male football referees. Thus, we can be closer to defining nutritional strategies of internal cooling, that will be an advantage for the performance of the football referees, concretely in the competitions carried out under adverse environmental conditions.

Conditions

Exercise Induced Hyperthermia; Performance Demands of Exercising in the Heat

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: DOUBLE

Study Groups

Intervention

A menthol solution is going to be formulated by crushing and dissolving one noncalorific menthol candy drop (15 mg) in 150 ml of warm water, in order to obtain a solution with a concentration of 0.01%. Prior to use, solutions are going to be aliquoted for mouth rinse and warmed at room temperature. Then, it will be served to each participant on individual bottles in a total dose of 75 ml before exercise and 75 ml during exercise.

Group Type: EXPERIMENTAL

Menthol solution

Intervention Type: OTHER

Menthol application, through oral solutions, stimulates the mandibular and maxillary branches of the trigeminal nerve (which are predominantly responsible for detection of temperature and nociceptive stimuli across the face and within the oral cavity) and has consistently shown to improve thermal comfort and decrease thermal sensation, which are thought to modulate perceived exertion to improve performance in the heat.

Placebo

A placebo beverage is going to be prepared using noncaloric berry-flavored sweetener consisting of sucralose candy drops, which will be crushed and dissolved in 150 ml of warm water. Prior to use, solutions are going to be aliquoted for mouth rinse and warmed at room temperature. Then, it will be served to each athlete on individual bottles in a total dose of 75 ml before exercise and 75 ml during exercise.

Group Type: PLACEBO_COMPARATOR

Menthol solution

Intervention Type: OTHER

Menthol application, through oral solutions, stimulates the mandibular and maxillary branches of the trigeminal nerve (which are predominantly responsible for detection of temperature and nociceptive stimuli across the face and within the oral cavity) and has consistently shown to improve thermal comfort and decrease thermal sensation, which are thought to modulate perceived exertion to improve performance in the heat.

Interventions

Menthol solution

Menthol application, through oral solutions, stimulates the mandibular and maxillary branches of the trigeminal nerve (which are predominantly responsible for detection of temperature and nociceptive stimuli across the face and within the oral cavity) and has consistently shown to improve thermal comfort and decrease thermal sensation, which are thought to modulate perceived exertion to improve performance in the heat.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

1. Male football referees aged over 18 and under 45 years;

2. With normal weight (BMI ≥ 18.5 and ≤ 24.9 kg/m2);

3. Availability to participate in the introductory meeting, familiarization session and 2 experimental sessions;

4. Ability to read and sign the informed consent.

Exclusion Criteria

1. Under the influence of any medications that may affect urinary parameters, thermoregulation mechanisms, circulatory system, thyroid and pituitary function or metabolic status;

2. Injury, diabetes, autoimmune disease, cardiovascular disease or obstructive disease of the gastrointestinal tract (e.g., diverticulitis, inflammatory bowel disease);

3. Schizophrenia, bipolar disorder or other psychotic disorders;

4. Eating disorders;

5. MRI scans scheduled within 48 hours after familiarization session or any of the experimental trials.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: No

Sponsors

Universidade do Porto

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

References

Roriz M, Brito J, Teixeira FJ, Spyrou K, Teixeira VH. The effect of menthol rinsing before intermittent exercise on physiological, physical, and thermo-behavioral responses of male football referees in hot and humid environment. Front Sports Act Living. 2024 Jan 22;6:1334739. doi: 10.3389/fspor.2024.1334739. eCollection 2024.

Reference Type: DERIVED

PMID: 38318484 (View on PubMed)

Roriz M, Brito J, Teixeira FJ, Spyrou K, Teixeira VH. Menthol mouth rinsing and performance in elite football referees in the heat: A study protocol for a randomized crossover trial. Contemp Clin Trials Commun. 2023 Aug 22;35:101202. doi: 10.1016/j.conctc.2023.101202. eCollection 2023 Oct.

Reference Type: DERIVED

PMID: 37691850 (View on PubMed)

Other Identifiers

20/2021/CEFCNAUP/2021

Identifier Type: -

Identifier Source: org_study_id