鼻音を含む剣道の「メン」の発声が鼻腔を経由した呼気一酸化窒素濃度に及ぼす影響

抄録

Nitric oxide (NO), an endogenous vasodilator that relaxes vascular endothelial cells and which is synthesized in the body, is primarily released from the sinuses into the nasal cavity during the continuous vocalization of “humming” nasal sounds. One of the vocalizations performed during kendo is “men”, which produces nasal sounds. We hypothesized that during these vocalizations, the fractional exhaled NO (FeNO) via the nasal cavity may increase. In this study, we measured FeNO through the nasal cavity of nine experienced kendo players when they vocalized “men” with a nasal sound in kendo. As a result, compared with humming (151.4±30.1 ppb), which involves continuous nasal sounds, the single vowel vocalization of “meeen” showed a significantly lower FeNO value (41.6±11.0 ppb, P＝0.005). However, the repeated vocalization of “men”, which consists of two repeated nasal sounds, showed a similar value to that during humming (141.9±25.2 ppb, P＝0.977). Our results illustrated that FeNO release via the nasal cavity increased during repeated vocalizations of “men” in one breath, such as during “kirikaeshi”. Therefore, we were able to further the current understanding of the physiological characteristics of the manner of kendo exercise.