Physiology and Biochemistry Breathing Pattern and Ventilatory Response to C02 during Exercise J. Mercier, M Ramonaixo, C. Préfaut Service d'Exploration de la Fonction Respiratoire, Hôpital Aiguelongue, Montpellier, France

J. Mercier, M Ramonatxo,C. Préfaut, Breathing Pattern and Ventilatory Response to C02 during Exercise. IntJSportsMed,Vol 13,No "pp 1—5,1992. Accepted after revision: March 15, 1991

The aim of this study was to determine during moderate exercise whether response to the C02 rebreathing test was dependent on differences in breathing pattern com-

ponents among individuals recorded before the test and whether differences in tidal volume response and/or breath-

ing frequency response to C02 during the test could influence their ventilatory response to C02. Ten healthy, sedentary male subjects, 20 to 34 years old, participated in the study. Ventilatory response to C02 was measured by the C02 rebreathing method (7% C02, 50% 02). The measurements of breathing pattern components and C02 rebreathing were made during mild steady state exercise: VCO2 = 20 mlkg — 1min . We measured the following: 1) tidal volume (VTex) and breathing frequency (fex) before C02 rebreathing and 2) ventilatory response to C02 (SVEex), tidal volume response to CO2 (SVTex), and breathing frequency response to C02 (Sfex) during the C02 rebreathing test. The

(r=0.89, p