Aerobic conditioning in mild asthma decreases the hyperpnea of exercise and improves exercise and ventilatory capacity.
OBJECTIVE
To determine the effect of an aerobic conditioning program on fitness, respiratory physiology, and resting lung function in patients with mild asthma.


METHODS
Prospective cohort study.


METHODS
Outpatient rehabilitation facility.


METHODS
Five patients with mild intermittent asthma and five normal control subjects completed a 10-week aerobic conditioning program. Pulmonary function studies and noninvasive cardiopulmonary exercise tests were performed before and after the conditioning program.


RESULTS
After aerobic conditioning, there were significant gains in maximum oxygen consumption (VO(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, control) and anaerobic threshold (0.99 L/min vs 1.09 L/min, p = 0.03, asthma; 0.89 L/min vs 1.13 L/min, p = 0.01, control) in both groups. Although FEV(1) 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 (VE) for each level of work was decreased in the asthma group after conditioning, while little change occurred in the control group (68. 48 L/min vs 51.70 L/min at initial VO(2)max, p = 0. 02, asthma; 65.82 L/min vs 63.12 L/min at initial VO(2)max, p = 0.60, control). A significant decrease in the ventilatory equivalent (VE/oxygen consumption, 40.8 vs 30.4 at VO(2)max, p = 0.02, asthma; 37.2 vs 35.8 4 at VO(2)max, p = 0.02, control) and the dyspnea index (VE/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 asthmatic and nonasthmatic participants of a 10-week aerobic fitness program. Additional benefits of improved ventilatory capacity and decreased hyperpnea of exercise occurred in patients with mild asthma.
Hallstrand
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Division of Pulmonary and Critical Care Medicine, University of Washington, Seattle, WA 98195-8673, USA. tealh@u.washington.edu
Bates
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Schoene
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D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D001249:Asthma / Q000503:physiopathology / Q000534:rehabilitation*; D002245:Carbon Dioxide / Q000378:metabolism; D015331:Cohort Studies; D004417:Dyspnea / Q000503:physiopathology / Q000517:prevention & control; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D006985:Hyperventilation / Q000517:prevention & control*; D008168:Lung / Q000503:physiopathology; D008297:Male; D008451:Maximal Voluntary Ventilation / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010313:Partial Pressure; D010809:Physical Fitness / Q000502:physiology*; D011446:Prospective Studies; D012126:Respiratory Dead Space / Q000502:physiology; D012143:Respiratory Physiological Phenomena; D013990:Tidal Volume / Q000502:physiology
D002245:Carbon Dioxide