Individualized Aerobic and High Intensity Training for Asthmatic Children (4)
Each gas analyzer was calibrated before and after each test with standard gases. The inspiratory airflow and the fractions of expired Og and CO* (Fe02 and FeCOJ were calculated by a computer from ten breath cycles. Averages were established for minute ventilation (Ve L.min _l BTPS), Ot uptake (Vo2 L.min _1 STPD), CO* production (Vco2 L.min STPD), respiratory ratio (R), ventilatory equivalent for 02 (Ve. Vo2_1) and C02 (Ve. Vco2_i), breathing frequency (f bpm), tidal volume (Vt L.min BTPS), inspiratory duty cycle (Ti/Ttot), and mean inspiratory flow (V*r/R L.s). The heart rate was determined on an electrocardiogram continuously recording on a cardioscope (Simonsen and Weel). Electrodes were placed in the C5M lead position. To account for interindividual differences in subjects, Ve, Vt, and Vt/Ii were normalized by body weight; for the same reason, the Vo2 was expressed in ml.kg.min.
The maximal exercise test started with a 3 min 30 W warm-up period. The work load was then increased by 30 W each minute (20 W for female subjects) until exhaustion. The observation of at least three of the four following criteria was necessary to consider that the subjects had reached their Vo2max: (1) stability of HR at a value close to the theoretical maximal heart rate; (2) stability of oxygen uptake in spite of the increase of work load; (3) respiratory ratio ^1.10; and (4) the inability of the subject to maintain a pedaling rate of 50 rpm. antibiotics levaquin
The ventilatory threshold (VTh) was determined as the last point before an increase in Ve.Vo2-1 plotted against a work rate without a concomitant Ve.Vco2-1 increase.