title: Continuous Vocalization during Kendo Exercises Suppresses Expiration of CO2.
abstract: One distinctive trait of kendo, the Japanese martial art of fencing, is the execution of sustained, high-effort vocalizations during actions. The purpose of this study was to determine the effect of these vocalizations on respiratory functions. First, the intensity of 3 kendo exercises was quantified by measuring oxygen uptake (V̇O2) and comparing it with V̇O2max measured during treadmill tests of 8 university kendo athletes. Respiratory variables of these 8 athletes were then analyzed using a portable breath gas analyzer during the most intensive kendo exercise, kakari-keiko, with and without vocalization. Breathing frequency (fB) increased regardless of vocalization, but in trials with vocalization, fB and ventilation were significantly lower, and expiration time was significantly longer. Components of expired gases were also affected by vocalization. Although there was no significant difference in oxygen uptake, vocalization yielded a reduction in carbon dioxide output (V̇CO2) and an increase in fraction of end-tidal carbon dioxide (FetCO2). We thus conclude that these vocalizations greatly affect expiration breathing patterns in kendo. Moreover, repetition of kakari-keiko caused a reduction in V̇CO2 and an increase in FetCO2 and CO2 storage. We consider the possibility that the sustained high-effort vocalizations of kendo also increase cerebral blood flow.
authors.affiliation: Department of Early Childhood Education, Chubu-gakuin College, Seki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Arikawa
authors.affiliation: Department of Physiology and Biophysics, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Terada
authors.affiliation: Department of Physiology and Biophysics, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Department of Orthopedic Surgery, Kurobe City Hospital, Kurobe, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kizaki
authors.affiliation: Department of Health and Physical Education, Faculty of Education, Gifu University, Gifu, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Imai
authors.affiliation: Department of Physiology and Biophysics, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Era
mesh_terms: D000293:Adolescent; D001944:Breath Tests / Q000379:methods; D002245:Carbon Dioxide / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D008297:Male; D016139:Martial Arts / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism; D012119:Respiration; D014831:Voice / Q000502:physiology*; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen