Effect of wearing mouthguards on the physical performance of soccer and futsal players: A randomized cross-over study

Aim: The aim of this study was to assess the influence of custom-fit mouthguards on the aerobic performance of soccer and futsal players under 17 (U-17). Material and methods: Forty players from 3 Brazilian clubs participated in the study. The athletes' aerobic performance was assessed through the 20-meter shuttle-run test. All athletes performed two tests with and without mouthguard. Two outcome variables were analyzed: (i) the total distance covered in the test (meters) and (ii) the maximum oxygen uptake (VO₂ max). A questionnaire assessing the level of acceptance of mouthguards considering different parameters was administered to the athletes before the delivery of the mouthguards and after 2 weeks of use. The questionnaire used a visual analogue scale (VAS). Paired t-test was used to compare the results obtained from the shuttle-run tests and the questionnaires. Results: Mouthguards did not influence the aerobic performance of the players, considering both the total distance covered in the tests and the VO₂ max. Stability was the parameter with the highest acceptance. Levels of acceptance regarding breathing (P = 0.022) and communication (P = 0.002) increased after mouthguards usage. Communication had the lowest level of acceptance considering all parameters assessed. Only 10% of the players reported receiving recommendations to use mouthguards while playing football or futsal. None of the participants reported having used mouthguards before. Conclusions: The use of custom-fit mouthguards does not affect the aerobic performance of soccer and futsal U-17 players. Future studies should focus on the development of appliances with maximum protection and minimum influence on communication.