Ventilatory response to erect and supine exercise

Autor: Hillis Ws, Clark Al, Terkelsen Ke
Rok vydání: 1999
Předmět:
Zdroj: Medicine & Science in Sports & Exercise. 31:1429
ISSN: 0195-9131
DOI: 10.1097/00005768-199910000-00011
Popis: Purpose: To test the hypothesis that altering the ventilation-perfusion ratio of the lung by changing the body position from erect to supine would alter the ventilatory response to exercise as described by the slope of the relationship between minute ventilation and carbon dioxide production. Methods: Ten normal subjects volunteers (5 female, 5 male: average age 22 yr; range 19-25 yr; height (SD) 173.5 (3.8) cm; weight 68.0 (3.3) kg) performed in random order erect and supine incremental cycle exercise with metabolic gas exchange measurements to determine peak oxygen consumption (VO 2 ) and the slope of the relation between ventilation and carbon dioxide production (VE/VCO 2 slope). Results: Subjects reached a higher peak VO 2 when erect (mean (SEM))(39.2 (2.4) vs 35.7 (2.0); P < 0.05). Heart rate, ventilation, and VO 2 were higher at each stage in the erect position. The respiratory exchange ratio was the same in each position at matched workloads and at peak exercise. The VE/VCO 2 slope was unchanged (27.8 (2.2) erect vs 27.7 (1.9) erect). Conclusion: Cycle exercise in the erect position is associated with an increase in exercise capacity compared with supine exercise but with no associated changes in ventilatory response to carbon dioxide production.
Databáze: OpenAIRE