LAUSR

BACKGROUND The importance of mouthguards for handball players has been proven however, most players are reluctant to use it. The impact on physical capacity is assessed heterogeneously in the literature. This study aimed to investigate the influence of custom-made mouthguards (CMGs) under handball specific stress. METHODS This randomized crossover study used data from 15 youth professional handball players (age 17.0 ±0.5 years, weight 85.1±8.0 kg and height 191.2±6.9 cm) who performed a validated handball specific course and a lung function test. Pulmonary (spirometry), metabolic (blood lactate), and cortisol parameters were observed using a normal custom-made mouthguard without (nCMG) and with respiratory channels (CMGvent) in comparison to no mouthguard (Co). RESULTS In resting spirometry, no differences in the parameter peak flow were observed using the CMGvent (9.57±1.59 l·s-1) and nCMG (9.17±1.03 l·s-1) in comparison to the Co (9.38±1.26 l·s-1). Under maximum stress, there were no differences in ventilation using CMGvent (151.2±15.64 L ·min-1), nCMG (148.6±12.51 l·min-1), and without mouthguard (145.8±14.32 l·min-1). Similar oxygen uptake was observed when using a CMGvent (45.51±4.14 L ·min-1·kg-1), nCMG (45.50±5.06 ml·min-1 ·kg-1), and without CMG (Co 43.90±4.02 mL ·min-1). The parameters of HR (CMGvent 185.2±11.63 bpm vs. Co 179.4±13.24 bpm p=0.46, nCMG 178.2±11.54 bpm vs. Co p=0.97; CMGvent vs. nCMG p=0.08) and in the blood lactate values (CMGvent: 9.66±2.3 mmol·l-1 vs. Co 9.07±2.1 mmol·l-1 p=0.63; nCMG 9.39±2.8 mmol·l-1 vs. Co p=0.87; CMGvent vs. nCMG p=0.91) displayed no differences. The cortisol production under stress showed no differences in the performance with the CMGvent (1.78±3.58 ng/ml), nCMG (0.74±4.52 ng/mL), and in the procedure without mouthguard (0.25. ±5.01 ng/ml). CONCLUSION The results showed that under stress, there were no differences in the cortisol, ventilation, cardiac, and metabolic responses for all three conditions. Finally, the study shows that the use of a custom-made mouthguard does not negatively affect handball specific performance. Due to the preventive aspect of the mouthguard, the use of a custom-made mouthguard in handball is strongly recommended.