Ventilatory Responses to Co2 Rebreathing at Rest and During Exercise in Untrained Subjects and Athletes

Miyamura, Miharu; Yamashina, Tadahiko; Honda, Yoshiyuki

doi:10.2170/jjphysiol.26.245

Cited by 44 publications

(17 citation statements)

References 22 publications

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“…The values for chemoreflex ventilation sensitivity that we measured in the current research ranged from 3.1 l min À1 mmHg À1 to 3.4 l min À1 mmHg À1 . These results are higher than those reported by other authors who have used the rebreathing method to measure chemoreflex ventilation sensitivity, for example, 1.1 l min À1 mmHg À1 in marathon runners (Miyamura 1976), 2.2 l min À1 mmHg À1 also for marathoners , 2.0 l min À1 mmHg À1 for swimmers (Heigenhauser et al 1983), and 2.4 l min À1 mmHg À1 for runners (Godfrey et al 1971). Our higher values are likely due to our tests being conducted in hypoxia (50 mmHg PO 2 ), as hypoxia has been shown to increase the slope of the ventilation-CO 2 response curve (Mohan and Duffin 1997), whereas tests in previous studies were performed in normoxia or hyperoxia (150-200 mmHg PO 2 ).…”

Section: Chemoreflex Responsecontrasting

confidence: 66%

Effects of concurrent inspiratory and expiratory muscle training on respiratory and exercise performance in competitive swimmers

et al. 2005

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The efficiency of the respiratory system presents significant limitations on the body's ability to perform exercise due to the effects of the increased work of breathing, respiratory muscle fatigue, and dyspnoea. Respiratory muscle training is an intervention that may be able to address these limitations, but the impact of respiratory muscle training on exercise performance remains controversial. Therefore, in this study we evaluated the effects of a 12-week (10 sessions week(-1)) concurrent inspiratory and expiratory muscle training (CRMT) program in 34 adolescent competitive swimmers. The CRMT program consisted of 6 weeks during which the experimental group (E, n = 17) performed CRMT and the sham group (S, n = 17) performed sham CRMT, followed by 6 weeks when the E and S groups performed CRMT of differing intensities. CRMT training resulted in a significant improvement in forced inspiratory volume in 1 s (FIV1.0) (P = 0.050) and forced expiratory volume in 1 s (FEV1.0) (P = 0.045) in the E group, which exceeded the S group's results. Significant improvements in pulmonary function, breathing power, and chemoreflex ventilation threshold were observed in both groups, and there was a trend toward an improvement in swimming critical speed after 12 weeks of training (P = 0.08). We concluded that although swim training results in attenuation of the ventilatory response to hypercapnia and in improvements in pulmonary function and sustainable breathing power, supplemental respiratory muscle training has no additional effect except on dynamic pulmonary function variables.

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Section: Chemoreflex Responsecontrasting

confidence: 66%

Effects of concurrent inspiratory and expiratory muscle training on respiratory and exercise performance in competitive swimmers

et al. 2005

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“…Byrne-Quinn et al (1971) observed diminished ventilatory responses to hypercapnic and hypoxic stimuli in 13 varsity athletes. Several authors have hitherto con®rmed that hypoxic and hypercapnic ventilatory responses were signi®cantly lower in well-trained runners and swimmers (Miyamura et al 1976;Ohkuwa et al 1980;Bjurstrom and Schoene 1987). Reduced ventilatory responsiveness to hypoxia and hypercapnia is considered to be attributable to decreased chemosensitivity of chemoreceptors through physical training for long periods (Blum et al 1979) because the hypercapnic ventilatory response was decreased by physical training and increased by detraining (Miyamura and Ishida 1990).…”

Section: Discussionmentioning

confidence: 99%

“…Several authors have reported that hypoxic and hypercapnic ventilatory responses are signi®cantly lower than normal in endurance runners and swimmers (Byrne-Quinn et al 1971;Miyamura et al 1976;Scoggin et al 1978;Ohkuwa et al 1980;Bjurstrom and Schoene 1987). This reduced ventilatory responsiveness in endurance athletes is considered to be due to decreased chemosensitivity through physical training.…”

Section: Introductionmentioning

confidence: 99%

Ventilatory response at the onset of voluntary exercise and passive movement in endurance runners

Miyamura

Ishida

Hashimoto

et al. 1997

European Journal of Applied Physiology

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The present study was performed to examine whether or not the ventilatory response at the onset of voluntary exercise and passive movement in endurance runners is the same as in untrained subjects. Twelve long-distance runners belonging to the varsity athletic club and 13 untrained subjects of our university participated as subjects in this study. Maximum oxygen uptake was significantly higher in the endurance runner group [mean (SD) 70.8 (4.7) ml.kg-1.min-1] than in the untrained group [49.8 (6.3) ml.kg-1.min-1]. Cardiorespiratory responses during voluntary exercise and passive movement of alternate flexion-extension of the right and left legs for about 15 s at a frequency of about 60 rpm, were determined by means of breath-by-breath techniques. Minute inspiratory ventilation (VI), tidal volume (VT), respiratory frequency (fb), cardiac output (Qc), stroke volume (SV) and heart rate (HR) increased significantly immediately at the onset of voluntary exercise and passive movement. The incremental rate for VI was greater than that for Qc. Average values and standard deviations of changes in VI were calculated as the difference between the mean of the first and second breath and the mean of five breaths preceding the exercise or movement. The rates obtained in voluntary exercise and passive movement in the endurance runner group [2.34 (0.82) and 1.72 (0.71 l.min-1), respectively] were significantly (P < 0.05) lower than those in the untrained group [4.16 (2.66) and 2.71 (1.56 l.min-1), respectively]. Also changes in VT and HR were significantly lower in the endurance group than in the untrained group with regard to both voluntary exercise and passive movement. The results suggest that the magnitude of cardiorespiratory responses at the onset of voluntary exercise and passive movement in humans is influenced by chronic endurance training for long periods.

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“…) in comparison with untrained subjects (1.86 and 2.03 l · min Ϫ1 · torr Ϫ1 ) [12,13]. Stanescu et al [1] observed that the mean slope (ϮSD) in the yoga group, 0.70Ϯ0.29 l · min Ϫ1 · torr Ϫ1 , was significantly (pϽ0.01) lower than in the control group (1.73Ϯ0.84 l · min Ϫ1 · torr…”

mentioning

confidence: 98%

Is Man Able to Breathe Once a Minute for an Hour?: The Effect of Yoga Respiration on Blood Gases.

Miyamura

Nishimura²,

Ishida³

et al. 2002

JJP

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Ventilatory Responses to Co2 Rebreathing at Rest and During Exercise in Untrained Subjects and Athletes

Abstract: Ventilatory responses to CO2

Cited by 44 publications

References 22 publications

Effects of concurrent inspiratory and expiratory muscle training on respiratory and exercise performance in competitive swimmers

Effects of concurrent inspiratory and expiratory muscle training on respiratory and exercise performance in competitive swimmers

Ventilatory response at the onset of voluntary exercise and passive movement in endurance runners

Is Man Able to Breathe Once a Minute for an Hour?: The Effect of Yoga Respiration on Blood Gases.

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