Background: Though jaw-repositioning devices have been found to increase size of upper respiratory airways in individuals, the effects of jaw-repositioning mouthguards on respiratory function during exercise have not been fully explored. The purpose of this study is to determine the effects of over-the-counter (OTC) jaw-repositioning mouthguards on respiratory function and aerobic performance in male athletes.
Methods: College-aged, male athletes (N.=20) participated in this randomized, crossover, controlled study. Each subject completed one testing session per condition: a no mouthguard control (CON), a placebo mouthguard (PLA), an OTC self-adapted jaw-repositioning mouthguard (SA), and an OTC custom-fitted jaw-repositioning mouthguard (CF). Each testing session consisted of respiratory flow dynamic tests at rest. Ventilation and gas exchange were assessed during a graded maximal treadmill test. Peak blood lactate values were obtained from 0-10 min post-exercise.
Results: At rest, the CON had significantly higher peak expiratory flow rate values than the other conditions (P<0.03). Maximum voluntary ventilation values for PLA and SA were significantly lower compared to CON (P<0.02) at rest. No significant differences were observed between conditions for ventilation, oxygen consumption, or carbon dioxide production during any submaximal stage (P=0.81) nor at maximal aerobic capacity (P=0.35). Peak lactate and adjusted peak lactate values were not significantly different between conditions (P=0.30 and P=0.63, respectively).
Conclusions: The OTC jaw-repositioning mouthguards in this study did not enhance aerobic performance. It is important to acknowledge that negative effects on aerobic performance were not observed, thus providing additional support for encouraging the use of this safety device in sports.