Aerobic conditioning in mild asthma decreases the hyperpnea of exercise and improves exercise and ventilatory capacity

Study objective: To determine the effect of an aerobic conditioning program on fitness, respiratory physiology, and resting lung function in patients with mild asthma. Design: Prospective cohort study. Setting: Outpatient rehabilitation facility. Methods: Five patients with mild intermittent asthma and five normal contro l subjects completed a 10-week aerobic conditioning program. Pulmonary func tion studies and noninvasive cardiopulmonary exercise tests were performed before and after the conditioning program. Results: After aerobic conditioning, there were significant gains in maximu m oxygen consumption ((V) over dot O(2)max; 22.73 mL/kg/min vs 25.29 mL/kg/ min, p = 0.01, asthma; 22.94 mL/kg/min vs 27.85 mL/kg/min, p = 0.03, contro l) and anaerobic threshold (0.99 L/min vs 1.09 L/min, p = 0.03, asthma; 0.8 9 L/min vs 1.13 L/min, p = 0.01, control) in both groups. Although FEV1 was unchanged, the maximum voluntary ventilation (MVV) improved in the asthma group (96.0 L/min vs 108.2 L/min, p = 0.08, asthma; 134.0 L/min vs 131.2 L/ min, p = 0.35, control). During exercise, minute ventilation ((V) over dot E) for each level of work was decreased in the asthma group after condition ing, while little change occurred in the control group (68.48 L/min vs 51.7 0 L/min at initial (V) over dot O(2)max, p = 0.02, asthma; 65.82 L/min vs 6 3.12 L/min at initial (V) over dot O(2)max, p = 0.60, control). A significa nt decrease in the ventilatory equivalent ((V) over dot E/oxygen consumptio n, 40.8 vs 30.4 at (V) over dot O(2)max, P = 0.02, asthma; 37.2 vs 35.8 4 a t (V) over dot O(2)max,max, p = 0.02, control) sand the dyspnea index ((V) over dot/MVV) at submaximal (0.44 vs 0.38, p = 0.05, asthma; 0.32 vs 0.38, p < 0.01, control) and maximal exercise (0.72 vs 0.63, p = 0.03, asthma; 0. 49 vs 0.62, p = 0.02, control) occurred in the asthma group. Conclusions: Exercise rehabilitation improves aerobic fitness in both asthm atic and nonasthmatic participants of a 10-week aerobic fitness program. Ad ditional benefits of improved ventilatory capacity and decreased hyperpnea of exercise occurred in patients with mild asthma.