Exercise and cardiovascular benefit in subjects with COPD: the need for randomised trials

measure aortic PWV occurred in a large proportion of patients at baseline (n551, 24%), which is not our or other groups' usual experience and may therefore have inadvertently generated bias.There is a great deal of heterogeneity between the studies published to date in terms of type and duration of exercise intervention, the magnitude of improvements in the functional outcome measures, inclusion of those with or without established cardiovascular disease, and the arterial bed assessed (carotid-femoral versus carotid-brachial), all of which undoubtedly will have contributed to the conflicting results.In the past, a similar controversy regarding the benefits of exercise intervention after myocardial infarction was resolved by the use of well-designed randomised controlled trials, which should be considered before discarding the likely cardioprotective role of pulmonary rehabilitation and the strong public health message of exercise improving cardiorespiratory health.