COMPARISON OF THE RESPIRATORY AND HEMODYNAMIC-RESPONSES OF HEALTHY-SUBJECTS TO EXERCISE IN 3 DIFFERENT PROTOCOLS

Although the importance of exercise testing has been well established, standardization of protocols is lacking. In the current study three p rotocols were compared with respect to respiratory and hemodynamic var iables at submaximal and peak exercise. Fifteen healthy young men unde rwent three maximal exercise tests using the following protocols. (I) an increase of 30 Watt, every three minutes; (II) an increase of 10 Wa tt, every minute; (III) a continuous load increase of 10 Watt/min. Res piratory measurements were made oi oxygen uptake (VO2), carbon dioxide output (VCO2), minute ventilation (V-E) and tidal volume (V-T). Hemod ynamic measurements were made of EGG, heart rate (HR), blood pressure and stroke volume (SV). The latter variable was measured by means of e lectrical impedance cardiography (EIC). There were no differences in m ean maximum load or peak-VO2 between protocols I, II and III. The cour se oi SV was similar in all protocols, i.e. an increase of about 30% u ntil 100 Watt, with a subsequent stabilization until maximum load. All other hemodynamic measurements were similar in both protocols, too. S ignificant differences were found in submaximal values of VO2 and VCO2 . There were no differences in other gas-exchange variables at any mom ent during exercise. With respect to the VO2 max or the hemodynamic re sponse to exercise, any protocol can be used. For the evaluation of su bmaximal exercise, the protocol that has been used has to be taken int o account. Differences at these levels are not related to differences in hemodynamic response.