Interventions
Exercise Group
Subjects attended three exercise classes each week for 6 weeks
in the Physiotherapy Department (Sir Charles Gairdner Hospital).
The classes lasted for 80–90 min and were supervised by a
physiotherapist. Any subjects requiring prophylactic bronchodilators
prior to exercise were instructed to take their medication
immediately prior to each class. Exercise was prescribed in accordance
with the recommendations for individuals with COPD [16] .
Specifically, classes commenced with a 10- to 15-min warm-up
comprising slow walking within a temperature-controlled corridor
and stretches. This was immediately followed by a 20-min
walking training prescribed at an initial intensity equivalent to
80% of the average walking speed achieved on the 6-min walking
test (6MWT) performed at the end of the run-in period (i.e. baseline
assessment) [16] . Subjects were permitted to take short rests
during the walking training if symptoms were intolerable. Following
a 5- to 10-min cool-down period that comprised a 150-metre
slow walk to the gymnasium, subjects participated in an exercise
circuit comprising cycle ergometry training for 10 min, stepups,
wall squats and upper limb endurance training for a total of
approximately 45 min. The target training intensity for the circuit
exercises was a rating of perceived exertion (RPE) of between 12
and 14 measured with the Borg 6–20 RPE scale [17] . When subjects
reported a higher RPE, they continued to exercise at this intensity
if their symptoms were tolerable. The intensity of the walking
training and circuit exercises was increased each week within
symptom tolerance [16] . The exercise program was extended to a
maximum of 10 weeks for subjects who experienced an exacerbation
of their asthma, or other problems, with the aim of subjects
completing at least 14 supervised training sessions within a maximum
of 10 weeks. All subjects randomised to the exercise group
continued to receive standard medical care for their asthma.
At the end of the training period, each subject was provided
with a written home exercise program based on the exercise intensities
achieved during their final training week. Subjects were
instructed to exercise on at least 3 days each week and were given
a diary card to record their exercise sessions.