Purpose:
The aim of this study was to evaluate the influence of three different mouthguards on the airflow dynamics of oral breathing under increased ventilatory conditions at peak workload.

Methods:
Twenty volunteer male martial art athletes were subjected to cardio-respiratory examination on a treadmill. Four trials were performed, without a mouthguard and with a maxillary boil-and-bite mouthguard, bi-maxillary boil-and-bite mouthguard, and PlaySafe custom-made maxillary mouthguard. For each of the four tests, subjects performed an identical incremental test to determine VO₂max and other respiratory values.

Results:
Collected data were analyzed using descriptive analyses and paired-samples t tests. The results indicated similarity in almost all measured variables when testing with the custom-made PlaySafe maxillary mouthguard to values recorded without a mouthguard, while tests performed with the maxillary and bi-maxillary boil-and-bite mouthguards showed greater differences.

Conclusions:
The custom-made PlaySafe maxillary and maxillary boil-and-bite mouthguards do not significantly reduce airflow dynamics of oral breathing when compared with the bi-maxillary boil-and-bite, instead, these two types of mouthguards were found to positively affect aerobic capacity.