Determining the metabolic load of walking in water compared to walking on land (over-ground) in people with COPD, who are normal weight or obese, compared to peak exercise metabolic response: a randomized cross-over pilot trial

Land-based exercise training is highly effective for improving exercise
tolerance and health status, and reducing hospital admissions, in people with
COPD. Unfortunately not all people with COPD are able to complete land-based
exercise training due to physical comorbidities such as obesity and/or
musculoskeletal conditions, which decrease tolerance to weight-bearing exercise
such as walking (Rutten et al 2013). Water-based exercise is a relatively new
modality for the rehabilitation of people with COPD and has been shown to be
safe and effective (McNamara et al 2013a), including in those who are obese
(McNamara et al 2013b), and is well accepted by patients (McNamara et al 2015).
A major advantage of exercise training in water is the unique properties of
buoyancy to support body weight, combined with resistance and turbulence to
movement in every direction (Becker 2009). Anecdotally, water-based exercise is
often perceived as a mode of exercise therapy that is easier and gentler than
land-based exercise and is often considered as being either less effective or
having no effect on cardiovascular fitness. However, the unique properties of
the water may result in people with COPD exercising at a higher intensity in
water than on land. Previous research has reported a higher subjective symptom
response to exercise in water compared to land in people with COPD (McNamara et
al 2013c). However, it is unknown whether higher symptom scores are due to
higher work intensity in water or to other aspects of the water environment. No
studies have evaluated the metabolic responses to exercise in water in people
with COPD to determine whether the exercise intensity is adequate to elicit
physiological training benefits.

The aim of this study is to evaluate the metabolic load during a single session
of moderate intensity walking in water compared to walking on land
(over-ground) in people with COPD who are normal weight and obese, compared
with peak exercise metabolic response.
The hypothesis is that the metabolic load of walking at a moderate intensity in
water will be greater than walking on land.

Randomised cross-over pilot trial.

Previous studies with similar measurements have shown that this testing
procedure will not lead to any adverse side effects or events. The participant
may experience some slight discomfort of the mask around their nose and mouth
area, and will be advised to notify the researchers if this discomfort becomes
too uncomfortable, in which case it will be removed.