Effect of a pulmonary rehabilitation program of 8 weeks duration compared to 12 weeks on exercise capacity in people with chronic obstructive pulmonary disease (PuRe Duration): A randomised controlled trial

Exercise training in a pulmonary rehabilitation program twice per week for 12 weeks. Programs are completed in an outpatient hospital setting and run by physiotherapists. Each training session will run for between 1 - 1.5 hours. Exercise training will consist of overground or treadmill walking, lower limb cycling, lower limb strengthening exercises (including body weight exercises; squats, sit to stands and step-ups and fixed weight exercises; leg press and leg extension) and upper limb exercises (including arm ergometry, lat pull-downs, chest press/fly and arm exercises with free weights). Initial exercise intensities will be standardised for each modality. Walking (overground or treadmill) will begin at 80% of peak walk speed determined by the six-minute walk test (6MWT) and progressed based on symptoms of dyspnoea and fatigue, with the aim of participants scoring a dyspnoea or fatigue score of at least 3-4 ('moderate' to 'somewhat severe') on the modified Borg dyspnoea 0-10 scale. Initial walking duration will be 10-15 minutes and progressed to 20-30 minutes between weeks 2-4. Lower limb cycling intensity will commence at 60% peak work rate using an equation based on the results of the 6MWT and progressed to 70% peak work rate based on symptoms of dyspnoea and fatigue, with the aim of participants scoring a dyspnoea or fatigue score of at least 3-4 on the modified Borg dyspnoea 0-10 scale. Arm ergometry will be performed for 10 minutes at a Borg score of 3-4 on the modified Borg dyspnoea 0-10 scale. Body weight lower limb strengthening exercises (squats, sit to stands and step ups) and arm free weight exercises will commence in week 2 at a load that can be achieved for 8 -10 repetitions before local muscle exhaustion. Fixed weight strengthening exercises for the lower limbs and upper limbs (leg extension, leg press, lat pull downs and chest press/fly) will commence in week 3 at a load that can be achieved for 8 -10 repetitions before local muscle exhaustion. By week 4, all strengthening exercise (body weight, free weight and fixed weight exercises) will be completed 3 times (i.e 3 sets). Resistances will be increased once participants can achieve 3 sets of 10 repetitions in two or more consecutive training sessions. Attendance will be monitored by the physiotherapists and participants will be encouraged to attend each allocated session.