Background: Ice hockey is a fast-paced sport with a high possibility of acquiring dental damage and concussions which can be prevented by mouthguards (MG). Despite this, many athletes choose not to use MG due to drawbacks such as discomfort and restricted airways. Restricted airways provided by MG might be reduced by external nasal dilator strips (ENDS). ENDS could contribute to increased aerobic capacity, blood oxygen saturation and self-reported compliance of ENDS by elevating airflow through the nose. Therefore, ENDS could contribute to enhanced performance and recovery rate while reducing the discomfort of MG that could lead to an increased usage of MG among healthy young adult ice hockey players. Aim: The aim was to study aerobic capacity, and oxygen saturation using mouthguard with and without external nasal dilator strips during submaximal bicycle tests. A second aim was to study the compliance of external nasal dilator strips when using mouthguard in healthy young adult ice hockey players. Method: In this experimental study using a cross-over design 15 young adult ice hockey players were contacted to attend on two separate test occasions, with and without ENDS. Aerobic capacity was measured with a Ekblom-Bak submaximal bicycle test (VO2max) and a pulse oximeter was used to examine oxygen saturation (%SpO2). Post-testing, the participants stated self-reported compliance using ENDS based on the numeric rating scale (0-10, positive-negative attitude of usage). Data are presented as mean and standard deviation. Differences between groups were analyzed with the Wilcoxon- signed rank test based on median (Q1-Q3). Result: Nine participants, aged 18-19 completed both test occasions. This study found that ENDS provided no significant difference in estimated VO2max mean (±SD), with ENDS 63.3 (±5.5) and without ENDS 64.2 (±5.0), nor %SpO2 during standard load. A significant increase showed in %SpO2 for higher individual load by 3%, with ENDS 97.1 (±1.3) and without ENDS 94.1 (±4.5). The participants experienced the test as more strenuous with ENDS than without ENDS applied, without significant difference. Despite this, the participants had a positive attitude towards the usage of ENDS. Conclusion This study regarding healthy young adult ice hockey players showed that ENDS provided no significant difference in aerobic capacity. Oxygen saturation however resulted in a positive significant difference at the higher individual load. The majority of the participants in this study propose a positive compliance with ENDS. The results are interpreted with caution due to the small sample.