What question did this study set out to answer?

Characterize the dynamic response patterns of ventilation, cardiac output, and pulmonary gas exchange during fluctuating and sudden exercise workloads.

January 1, 1983The Japanese Journal of PhysiologyOpen Access

Cardiorespiratory dynamics during sinusoidal and impulse exercise in man.

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Population

5 healthy young men, ranging in age from 22 to 28 years, weight from 55 to 65 kg, and height from 165 to 175…

Design

Other

Authors

YMYoshimi MiyamotoYamagata University YNYoshimi NakazonoAoyama Gakuin University THT. HiuraMitsubishi Group (Japan)

Discussion

Member takes

Implication

Offers no immediate clinical guidance; leaves open the cardiodynamic hypothesis for unsteady-state exercise hyperpnea.

Key Points

Characterize the dynamic response patterns of ventilation, cardiac output, and pulmonary gas exchange during fluctuating and sudden exercise workloads.
Tested five healthy men in an upright position performing bicycle ergometer exercise under sinusoidally varying (1 to 12 minute periods) and 10-second impulse work rates.
Continuously monitored stroke volume, heart rate, and cardiac output via impedance cardiography alongside breath-by-breath gas exchange and minute ventilation.
Utilized frequency analysis techniques to derive amplitude and phase relations, modeling responses with first-order and second-order dynamic systems.
Sinusoidal exercise responses fit first-order models with average time constants of 75 seconds for ventilation, 67 seconds for VCO2, 52 seconds for VO2, and 36 seconds for cardiac output.
Impulse exercise responses followed second-order models featuring parallel fast and slow components, with the fast component contributing minimally to the overall response.
Ventilation dynamics coupled closely to carbon dioxide output during both sinusoidal and impulse protocols, indicating hyperpnea in unsteady exercise reflects cardiodynamic mechanisms.

Structured PICO

Population

5 healthy young men, ranging in age from 22 to 28 years, weight from 55 to 65 kg, and height from 165 to 175 cm.

Intervention

Sinusoidally varying work rates (oscillating between 25 and 125W around 75W for periods from 1 to 12 min) and impulse work rate (10 sec duration) on a bicycle ergometer.

Outcome

Dynamic characteristics (amplitude, phase relations, and time constants) of ventilation, cardiac output, and gas exchange.surrogate

A tight linkage between minute ventilation and carbon dioxide output responses to impulse stimuli supports the cardiodynamic hypothesis to explain hyperpnea during unsteady-state exercise.

Cite This Study

Miyamoto et al. (1983) studied this question.

synapsesocial.com/papers/6a9650d7dbc641e6a0a6b3e8 https://doi.org/10.2170/jjphysiol.33.971

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Cardiorespiratory dynamics during sinusoidal and impulse exercise in man.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Cardiorespiratory dynamics during sinusoidal and impulse exercise in man.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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