The Effect of a Respiratory Muscle Warm-up Prior to Exercise in Patients With Chronic Obstructive Pulmonary Disease

The Effect of a Respiratory Muscle Warm-up Prior to Exercise in Patients With Chronic Obstructive Pulmonary Disease (COPD)

The purpose of this study is to investigate the effects of performing a breathing muscle warm up before exercise in patients who have chronic obstructive pulmonary disease (COPD). The main aim is to see whether performing a breathing muscle warm up can improve distance walked in a 6 minute walk test and also decrease perceptions of effort and breathlessness.

The study will follow a counter-balanced repeated measures design involving six visits to the exercise laboratory. Following pre-screening and familiarisation (visits 1 and 2), participants will perform inspiratory warm up, expiratory warm up, combination warm up and control trials (visits 3 - 6) in a counter-balanced order separated by at least 48 hours between trials.

The four separate sessions will contain: lung function measurements assessed by performing breathing manoeuvres through a mouthpiece (spirometery or body plethysmography) before performing a breathing muscle warm up by breathing against a resistance through a small handheld device (PowerLung). Participants will then be asked perform a second set of lung function measurements and will then be asked to perform a 6 minute walk test wearing a face mask and a portable device (gas analysis), a small device clipped to a finger (pulse oximeter) and wearing a heart rate monitor. During this 6 minute walk test participants will also be asked to rate their perceived effort and level of breathlessness at 60m intervals. Following the test there will be a period of seated rest wearing the face mask and portable device for up to 20 minutes with one more set of lung function measurements.

Inclusion Criteria:

• A clinical diagnosis of COPD
• Aged between 35 and 90 years
• Able to fluently read and speak English
• Willing and able to sign informed consent
• Be able to comply with the procedures outlined for the study

Exclusion Criteria:

• Cardiac disease (including arrhythmias)
• A medicinal requirement for rate limiting calcium antagonists or beta blockers
• Cerebrovascular disease
• Peripheral vascular disease
• Requirement for supplemental oxygen therapy
• CO2 (carbon dioxide) retention
• Malignancy
• Orthopaedic or neurological conditions effecting the ability to exercise
• Clinically apparent heart failure
• Renal, hepatic or inflammatory disease
• Instability of COPD
• Any other reason leading to the inability to complete the requirements of the study.

Additionally: If participants have a resting HR above 120beats.min-1, systolic blood pressure above 180mm Hg or diastolic blood pressure above 100mm Hg prior to the 6 minute walk test they will not be able to commence the test.