TY - JOUR
T1 - Disappearance of isocapnic buffering period during increasing work rate exercise at high altitude
AU - Agostoni, Piergiuseppe
AU - Valentini, Mariaconsuelo
AU - Magrì, Damiano
AU - Revera, Miriam
AU - Caldara, Gianluca
AU - Gregorini, Francesca
AU - Bilo, Grzegorz
AU - Styczkiewicz, Katarzyna
AU - Savia, Giulio
AU - Parati, Gianfranco
PY - 2008/6
Y1 - 2008/6
N2 - BACKGROUND: At sea level, ventilation kinetics are characterized during a ramp exercise by three progressively steeper slopes, the first from the beginning of exercise to anaerobic threshold, the second from anaerobic threshold to respiratory compensation point, and the third from respiratory compensation point to peak exercise. In the second ventilation phase, body CO2 stores are used to buffer acidosis owing to lactate production; it has been suggested that this extra CO2 production drives the ventilation increase. At high altitude, ventilation increases owing to hypoxia. We hypothesize that ventilation increase reduces body CO2 stores affecting ventilation kinetics during exercise. DESIGN: In eight healthy participants, we studied the ventilation kinetics during an exercise performed at sea level and at high altitude (4559 m). METHODS: We used 30 W/2 min step incremental protocol both at sea level and high altitude. Tests were done on a cyclo-ergometer with breath-by-breath ventilation and inspiratory and expiratory gas measurements. We evaluated cardiopulmonary data at anaerobic threshold, respiratory compensation point, peak exercise and the VE/VCO2 slope. RESULTS: At high altitude: (a) peak VO2 decreased from 2595±705 to 1745±545 ml/min (P
AB - BACKGROUND: At sea level, ventilation kinetics are characterized during a ramp exercise by three progressively steeper slopes, the first from the beginning of exercise to anaerobic threshold, the second from anaerobic threshold to respiratory compensation point, and the third from respiratory compensation point to peak exercise. In the second ventilation phase, body CO2 stores are used to buffer acidosis owing to lactate production; it has been suggested that this extra CO2 production drives the ventilation increase. At high altitude, ventilation increases owing to hypoxia. We hypothesize that ventilation increase reduces body CO2 stores affecting ventilation kinetics during exercise. DESIGN: In eight healthy participants, we studied the ventilation kinetics during an exercise performed at sea level and at high altitude (4559 m). METHODS: We used 30 W/2 min step incremental protocol both at sea level and high altitude. Tests were done on a cyclo-ergometer with breath-by-breath ventilation and inspiratory and expiratory gas measurements. We evaluated cardiopulmonary data at anaerobic threshold, respiratory compensation point, peak exercise and the VE/VCO2 slope. RESULTS: At high altitude: (a) peak VO2 decreased from 2595±705 to 1745±545 ml/min (P
KW - Exercise
KW - High altitude
KW - Isocapnic buffering period
KW - Ventilation kinetics
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U2 - 10.1097/HJR.0b013e3282f62982
DO - 10.1097/HJR.0b013e3282f62982
M3 - Article
C2 - 18525393
AN - SCOPUS:56149096989
VL - 15
SP - 354
EP - 358
JO - European Journal of Cardiovascular Prevention and Rehabilitation
JF - European Journal of Cardiovascular Prevention and Rehabilitation
SN - 1741-8267
IS - 3
ER -