Aerobic Conditioning in Mild Asthma Decreases the Hyperpnea of Exercise and Improves Exercise and Ventilatory Capacity

摘要

Study objective: To determine the effect of an aerobic conditioning program on fitness,nrespiratory physiology, and resting lung function in patients with mild asthma.nDesign: Prospective cohort study.nSetting: Outpatient rehabilitation facility.nMethods: Five patients with mild intermittent asthma and five normal control subjects completedna 10-week aerobic conditioning program. Pulmonary function studies and noninvasive cardiopulmonarynexercise tests were performed before and after the conditioning program.nResults: After aerobic conditioning, there were significant gains in maximum oxygen consumptionn(V˙ O2max; 22.73 mL/kg/min vs 25.29 mL/kg/min, p 5 0.01, asthma; 22.94 mL/kg/min vs 27.85nmL/kg/min, p 5 0.03, control) and anaerobic threshold (0.99 L/min vs 1.09 L/min, p 5 0.03,nasthma; 0.89 L/min vs 1.13 L/min, p 5 0.01, control) in both groups. Although FEV1 wasnunchanged, the maximum voluntary ventilation (MVV) improved in the asthma group (96.0 L/minnvs 108.2 L/min, p 5 0.08, asthma; 134.0 L/min vs 131.2 L/min, p 5 0.35, control). During exercise,nminute ventilation (V˙ E) for each level of work was decreased in the asthma group afternconditioning, while little change occurred in the control group (68.48 L/min vs 51.70 L/min atninitialV˙ O2max, p 5 0.02, asthma; 65.82 L/min vs 63.12 L/min at initialV˙ O2max, p 5 0.60, control).nA significant decrease in the ventilatory equivalent (V˙ E/oxygen consumption, 40.8 vs 30.4 atnV˙nO2max, p 5 0.02, asthma; 37.2 vs 35.8 4 at V˙ O2max, p 5 0.02, control) and the dyspnea indexn(V˙ E/MVV) at submaximal (0.44 vs 0.38, p 5 0.05, asthma; 0.32 vs 0.38, p < 0.01, control) and maximalnexercise (0.72 vs 0.63, p 5 0.03, asthma; 0.49 vs 0.62, p 5 0.02, control) occurred in the asthma group.nConclusions: Exercise rehabilitation improves aerobic fitness in both asthmatic and nonasthmaticnparticipants of a 10-week aerobic fitness program. Additional benefits of improved ventilatoryncapacity and decreased hyperpnea of exercise occurred in patients with mild asthma.