title: Forced respiration during the deeper water immersion causes the greater inspiratory muscle fatigue in healthy young men.
abstract: [Purpose] The purpose of the present study was to evaluate the effect of water immersion at different water depths on respiratory function and the effect of inspiratory load breathing (ILB) during water immersion at different water depths on respiratory muscle strength evaluated by maximum inspiratory and expiratory pressures (PImax and PEmax, respectively). [Subjects] Eight healthy men participated randomly in three trials. [Methods] All sessions were conducted with the participants in a sitting position immersed in a water bath. We evaluated respiratory function, PImax and PEmax during submersion at three different levels of water depth (umbilicus; 4th-rib; or clavicle, CL) and after subsequent 15-min ILB. [Results] Decreases in vital capacity and expiratory reserve volume from baseline by water immersion were significantly greater in the CL trial than those in the other trials. In the CL trial, PImax was immediately reduced after ILB compared to that at baseline, and the reduction was significantly greater than those in the other trials. PEmax was not affected by ILB in any of the trials. [Conclusion] Forced respiration during deeper water immersion caused greater inspiratory muscle fatigue in healthy young men.
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Yamashina
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Hisayo
authors.initials: H
authors.lastname: Yokoyama
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Nooshin
authors.initials: N
authors.lastname: Naghavi
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Hirasawa
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Takeda
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Akemi
authors.initials: A
authors.lastname: Ota
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Imai
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miyagawa
authors.affiliation: Environmental Physiology for Exercise, Osaka City University Graduate School of Medicine, Japan.
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Okazaki
keywords: Aquatic exercise; Inspiratory load breathing; Respiratory muscle strength