title: Response of end tidal CO2 pressure to impulse exercise.
abstract: The purpose of the present study was to examine how end tidal CO(2) pressure (PETCO(2)) is controlled in impulse exercise. After pre-exercise at 25 watts for 5 min, impulse exercise for 10 sec with 200 watts followed by post exercise at 25 watts was performed. Ventilation (VE) significantly increased until the end of impulse exercise and significantly re-increased after a sudden decrease. Heart rate (HR) significantly increased until the end of impulse exercise and then decreased to the pre-exercise level. PETCO(2) remained constant during impulse exercise. PETCO(2) significantly increased momentarily after impulse exercise and then significantly decreased to the pre-exercise level. PETCO(2) showed oscillation. The average peak frequency of power spectral density in PETCO(2) appeared at 0.0078 Hz. Cross correlations were obtained after impulse exercise. The peak cross correlations between VE and PETCO(2), HR and PETCO(2), and VE and HR were 0.834 with a time delay of -7 sec, 0.813 with a time delay of 7 sec and 0.701 with a time delay of -15 sec, respectively. We demonstrated that PETCO(2) homeodynamics was interactively maintained by PETCO(2) itself, CO(2) transportation (product of cardiac output and mixed venous CO(2) content) into the lungs by heart pumping and CO(2) elimination by ventilation, and it oscillates as a result of their interactions.
authors: Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku Sapporo Japan.
authors: T
authors: T
authors: Yano
authors: Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku Sapporo Japan.
authors: R
authors: R
authors: Afroundeh
authors: Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku Sapporo Japan.
authors: R
authors: R
authors: Yamanak
authors: Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku Sapporo Japan.
authors: T
authors: T
authors: Arimitsu
authors: Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku Sapporo Japan.
authors: C-S
authors: CS
authors: Lian
authors: Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku Sapporo Japan.
authors: K
authors: K
authors: Shirkawa
authors: Hokkaido University Laboratory of Exercise Physiology, Faculty of Education Kita-ku Sapporo Japan.
authors: T
authors: T
authors: Yunoki
mesh_terms: D002245:Carbon Dioxide / Q000097:blood / Q000378:metabolism*; D002302:Cardiac Output; D015444:Exercise; D006339:Heart Rate; D006706:Homeostasis; D006801:Humans; D008168:Lung / Q000378:metabolism / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D011312:Pressure; D012123:Pulmonary Ventilation; D013997:Time Factors; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide
keywords: end-tidal CO2 pressure; heart rate; impulse exercise; oscillation; ventilation