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.
