Utilizing nasal breathing during aerobic exercise significantly improves respiratory performance

Nasal breathing (NB) during aerobic exercise may improve respiratory performance more effectively than utilizing combined breathing (CB). To examine adaptations in respiratory performance following four weeks of aerobic exercise while utilizing NB. 22 males (age: 21.55 ± 2.58 years) were block-randomized into a CB or NB group. Participants performed a spirometry and graded maximal aerobic exercise test (GXT) during Pre-training (V1), and after four weeks of supervised moderate-intensity aerobic exercise sessions (Post-training, V2). Respiratory gases were collected with a metabolic cart. Repeated measures ANOVA with Bonferroni correction were utilized to analyze all data with a significance set at p < 0.05. From V1 to V2, the NB group improved their forced expiratory volume 1.0 (V1: 4.33 ± 0.64 L; V2: 4.47 ± 0.67 L, p = 0.033). Post-training, the NB group had a higher oxygen uptake (V1: 31.96 ± 4.21 ml·kg −1 ·min −1 ; V2: 35.96 ± 4.29 ml·kg −1 ·min −1 , p = 0.004). Compared to the CB (93.22 ± 20.88 L·min −1 ) at V2, the NB (72.03 ± 11.74 L·min −1 ) group had a lower ( p = 0.008) ventilation (V̇E). Four weeks of moderate-intensity aerobic exercise utilizing NB increased respiratory efficiency, leading to a higher V̇O 2 at a lower V̇E.