Physiological Response to Moderate Exercise Workloads in a Pulmonary Rehabilitation Program in Patients With Airflow Obstruction: Conclusion
The design of the initial training prescription in the present study was similar to that described by Niederman et al, who exercised 33 patients with a wide spectrum of airflow limitation (FEV1 range, 0.33 to 3.8 L) three times a week for 9 weeks. It was shown that changes in maximal and submaximal exercise performance on a bicycle ergometer were not related to the magnitude of airflow impairment quantified as % predicted FEV1. In the present study, we were able to develop these observations in a larger cohort of patients but with a comparable wide spectrum of airflow limitation (FEV1 range, 0.51 to 2.99 L). Our data show that training benefits are unrelated to and independent of underlying airflow limitation; comparable benefits were observed for patients with % predicted FEV1 < 40% and for those whose FEV1 exceeded this threshold (Table 4). Interestingly, in contrast to previous studies, there was a significant but very modest clinical impact on dynamic and static lung volumes. Even though the exercise program did not include weight training as a component, it is difficult to attribute the improvements in ventilatory capacity to the training schedule per se. A more likely explanation relates to indirectly derived educational benefits in the use of inhaled medication. generic zyrtec
Primary outcome measures in pulmonary rehabilitation strategies include assessments of quality of life and psychosocial performance, quantification of domestic functional activity, in addition to the physiologic benefit derived from aerobic training. This study further emphasizes the important role of aerobic submaximal exercise training in patients with chronic pulmonary morbidity. Although the magnitude of the physiologic benefits observed in reducing ventilatory requirements may be considered small, they were nevertheless achieved irrespective of the degree of airflow limitation, and this has significant implications for clinical practice. We are unable to quantify which particular aspect of the exercise strategy is more important; additionally, we are unable to state with certainty whether or not the observed physiologic gains are directly extrapolatable to improved functional daily activity, since this was not our primary outcome measure. It is nevertheless likely, however, that in patients limited by dyspnea, peripheral muscle weakness and increased susceptibility to lactic acidosis, enhancement of exercise tolerance, and reduction in ventilatory and cardiovascular requirements at a defined level of exercise will extrapolate to improved domestic functioning. Of note, a recent study by Singh et al did demonstrate objective improvements in domestic function following a rehabilitation strategy that resulted in improved exercise tolerance.
In summary, these data expand on the physiologically based principles of exercise prescription for patients with chronic airflow limitation and endorses the benefit of such strategies. We have shown that submaximal aerobic exercise training of moderate intensity performed twice weekly for 12 weeks in a large cohort of patients has significant potential benefits on a number of physiologic responses irrespective of the severity of the underlying obstructive pulmonary disease. The implications for clinical practice are tangible and compelling.
Category: Airflow Obstruction
Tags: COPD, exercise training, pulmonary rehabilitation