The measurements made at baseline will be repeated at 3 and 12 months. Of note, as this study is a prospective longitudinal study, patients will be familiarised with the exercise tests in the days before discharge to minimise learning effect. Verbal encouragement during exercise testing will be standardised to avoid researcher effects. The assessor will be blinded to the subject's intervention. However owing to the nature of the intervention, it will not be possible to blind the subjects to their intervention.