The effects of aerobic and ventilatory muscle training on pulmonary function and submaximal work performance in subjects with pre-clinical chronic obstructive pulmonary disease

The purpose of this study was to determine the effects of aerobic training and ventilatory muscle training on pulmonary function and submaximal work performance in subjects with pre-clinical chronic obstructive pulmonary disease (COPD). Thirty-seven subjects were assigned to one of four test groups: a control, aerobic training, ventilatory training and a combination of aerobic/ventilatory training. Following a period of habituation the subjects were given pre-training tests of pulmonary function and submaximal work performance. A training period of six weeks duration followed in which the subjects' training programs were strictly monitored. Aerobic trainers rode a bicycle ergometer three times a week for a specified period of time and with a prescribed heart rate. The ventilatory trainers ventilated on a re-breathing tube five days a week for a prescribed period of time. Following the training period identical post-training tests of pulmonary function and submaximal work performance were administered. The aerobic and aerobic/ventilatory groups demonstrated an improvement in submaximal work performance with a reduction in post-training heart rate (HR) at a given workload. The ventilatory and aerobic/venti1atory groups exhibited an increase in maximum voluntary ventilation for 10 seconds (MVV₁₀) in their post-training tests. The results of this study indicate that it is possible for subjects with pre-clinical COPD to demonstrate improvement in submaximal work performance as a result of proper training independent of changes in pulmonary function. It also demonstrates that these same subjects can show improvement in MVV₁₀ with appropriate training independent of changes in submaximal work performance. Combining the aerobic bicycle training and the ventilatory muscle training did not result in a more significant increase in MVV₁₀ than did the ventilatory muscle training alone, or a greater decrease in the HR during submaximal exercise than did the aerobic bicycle training alone.