Morton A R, King K, Papalia S, Goodman C, Turley K R, Wilmore J H
University of Western Australia, Perth, Australia.
Aust J Sci Med Sport. 1995 Sep;27(3):51-5.
The major cause of exercise-induced asthma (EIA) is thought to be the drying and cooling of the airways during the 'conditioning' of the inspired air. Nasal breathing increases the respiratory system's ability to warm and humidity the inspired air compared to oral breathing and reduces the drying and cooling effects of the increased ventilation during exercise. This will reduce the severity of EIA provoked by a given intensity and duration of exercise. The purpose of the study was to determine the exercise intensity (%VO2 max) at which healthy subjects, free from respiratory disease, could perform while breathing through the nose-only and to compare this with mouth-only and mouth plus nose breathing. Twenty subjects (11 males and 9 females) ranging from 18-55 years acted as subjects in this study. They were all non-smokers and non-asthmatic. At the time of the study, all subjects were involved in regular physical activity and were classified, by a physician, as free from nasal polyps or other nasal obstruction. The percentage decrease in maximal ventilation with nose-only breathing compare to mouth and mouth plus nose breathing was three times the percentage decrease in maximal oxygen consumption. The pattern of nose-only breathing at maximal work showed a small reduction in tidal volume and large reduction in breathing frequency. Nasal breathing resulted in a reduction in FEO2 and an increase in FECO2. While breathing through the nose-only, all subjects could attain a work intensity great enough to produce an aerobic training effect (based on heart rate and percentage of VO2 max).
运动诱发性哮喘（EIA）的主要原因被认为是在吸入空气“调节”过程中气道的干燥和冷却。与口呼吸相比，鼻呼吸可增强呼吸系统对吸入空气的加温加湿能力，并减轻运动期间通气增加带来的干燥和冷却效应。这将减轻由特定强度和时长的运动诱发的EIA的严重程度。本研究的目的是确定无呼吸道疾病的健康受试者仅通过鼻呼吸时能够达到的运动强度（%最大摄氧量），并将其与仅通过口呼吸以及口鼻同时呼吸进行比较。20名年龄在18至55岁之间的受试者（11名男性和9名女性）参与了本研究。他们均不吸烟且无哮喘。在研究期间，所有受试者都有规律地进行体育活动，且经医生判定无鼻息肉或其他鼻腔阻塞问题。与口呼吸和口鼻同时呼吸相比，仅通过鼻呼吸时最大通气量的下降百分比是最大耗氧量下降百分比的三倍。在最大负荷运动时，仅通过鼻呼吸的模式显示潮气量略有减少，呼吸频率大幅降低。鼻呼吸导致呼气末氧分压降低，呼气末二氧化碳分压升高。仅通过鼻呼吸时，所有受试者都能达到足以产生有氧训练效果的运动强度（基于心率和最大摄氧量百分比）。
