Feasibility of Interval Exercise in Bronchiectasis
Condition: Bronchiectasis
MeSH terms: Bronchiectasis
Study type: Interventional

Summary: 
      Research to date suggests that encouraging increased physical activity and exercise
      engagement may be an effective way to improve symptoms, fitness, quality of life, and reduce
      time spent in hospital for bronchiectasis sufferers. However, relatively few patients
      continue to engage with exercise programs that are of benefit to their health and symptoms.
      Barriers to exercise are thought to include time constraints and the use of specialist
      equipment (e.g. cycle ergometers) which may not be available or accessible in the home (or
      hospital) setting. With these points in mind, there is growing interest in brief, relatively
      intense, interval exercise interventions for chronic lung disease sufferers as they require
      minimal equipment and may more easily translate back into the home setting. Of the types of
      approach this might include, both stair-based and walk-based interval exercise appear to be
      relatively safe, practical, and time-efficient ways to improve physical fitness and quality
      of life in previously untrained and clinical populations. However, the feasibility and
      effectiveness of their use by chronic lung disease patients, particularly those with
      bronchiectasis, is yet to be properly examined. The investigators therefore intend to recruit
      10 bronchiectasis patients to explore the feasibility and effectiveness of minimal-equipment
      interval exercise interventions in this population. More specifically, the investigators
      would like to observe patients' acute physical and perceptual responses to four different
      step and walk-based protocols which have been established for other clinical populations. The
      investigators also wish to explore whether these protocols are engaged with, and enjoyed,
      during a six week unsupervised exercise intervention (in the home), as well as the effects of
      this six week unsupervised exercise period on physical fitness. This project will hopefully
      make a valuable contribution to the limited research to have examined the real-world
      application and impact of interval-type exercise interventions on exercise behaviour, health,
      and symptoms in bronchiectasis sufferers.
    

Detailed description: 
      Baseline testing (Visit 1) Having completed informed consent and screening, participants will
      be invited to complete a hospital-based baseline physiological testing session. The usual
      care of this participant group means that a clinical assessment of condition severity and
      associated spirometry measures (e.g. peak flow, forced vital capacity) will have already been
      completed which will be included in the study data. If this is not the case, then a member of
      the patient's usual care team (which may include members of the research team) will collect
      these baseline measures. Baseline physiological assessment will then be completed, including
      a self-paced six minute walk test (6MWT); an Isometric Quadriceps Strength Test (IQST); and
      an incremental, externally paced, symptom-limited Chester Step Test (CST ). Peak values for
      cardiorespiratory measures (i.e. heart rate, oxygen consumption and saturation, minute
      ventilation) will be established by way of clinically validated metabolic cart, oximeter and
      facemask applied during the incremental CST. Each of these tests will be delivered in the
      stated order across a 60 minute period, with each test followed by at least 5 minutes of rest
      to allow for adequate recovery and instruction.

      Acute high-intensity interval exercise trials (Visits 2-5) Four subsequent hospital-based
      (supervised) trials will require participants to complete differing formats of step-based or
      walking-based HIIE, in a randomised order established by an online random sequence generator.
      Mean and peak values for cardiorespiratory responses (i.e. heart rate, oxygen consumption,
      minute ventilation) will be established by way of clinically validated metabolic cart and
      face-mask applied for the duration of each protocol. Whilst the same format of each HIIE
      session will prescribed to each participant, their completion of each work and rest period
      (and the duration of these) will be subject to symptom limitation (i.e. they will be
      permitted to shorten work and/or extend rest periods if symptoms dictate).

      Post-HIIE questions will be verbally asked of participants at the end of each exercise
      session, including;

      Did they enjoy this type of exercise? Would they like to try this exercise at home? Did they
      feel safe when completing this exercise? What will be the major barrier for them to not try
      this exercise at home?

      In addition to their initial responses, participants will be invited to offer a brief
      explanation as appropriate. All responses will be recorded by dictaphone and subsequently
      transcribed by a member of the research team for later analysis.

      Unsupervised 6 week high-intensity interval exercise intervention Having completed all acute
      high-intensity interval exercise trials, participants will then complete 6 weeks of
      home-based unsupervised exercise, initially incorporating their preferred format of stair
      and/or walking-based HIIE, three days per week. They will be encouraged to gradually progress
      exercise load (i.e. repetitions, work-to-rest ratio, and/or sessions per week) to a maximum
      of 6 x 60 seconds, five times per week (i.e. ~12 minutes total). Measures of physiological
      status, symptoms and well-being will be logged throughout (i.e. heart rate, dyspnea,
      respiratory quality of life, anxiety and depression).

      Follow-up testing (Visit 6) Upon completion of home-based unsupervised exercise intervention,
      baseline physiological assessments will be repeated in the hospital setting. This will again
      include a self-paced MWT; an IQS test; and an incremental, externally paced, symptom-limited
      CST. Peak values for cardiorespiratory measures (i.e. heart rate, oxygen consumption, minute
      ventilation) will be established by way of clinically validated metabolic cart and facemask
      applied during the incremental CST. Each of these tests will be delivered in the stated order
      across a 60 minute period, with each test followed by at least 15 minutes of rest to allow
      for adequate recovery and instruction.

      Following a similar approach to pre-intervention testing, post-intervention questions will be
      verbally asked of participants at the end of the follow up testing session, including; Did
      they enjoy this exercise intervention? Would they like to continue these types of exercise at
      home? Did they feel safe when completing these exercises at home? What will be the major
      barrier for them to not continue these types of exercise at home? What changes would make
      continuing this type of exercise more appealing to them?

      In addition to their initial responses, participants will be invited to offer a brief
      explanation as appropriate. All responses will be recorded by dictaphone and subsequently
      transcribed by a member of the research team for later analysis.
    

Intervention name(s): Step and walk-based high intensity interval exercise
Intervention type(s): Other
Intervention description(s): Four hospital-based trials will include two step-based (3 x 20 sec with 120 sec rest, or 3 x 60 sec with 60 sec rest) and two walking-based (e.g. 3 x 60 sec with 60 sec rest or 3 x 180 sec with 180 sec rest) interval exercise protocols, in a randomised and counterbalanced order.
Unsupervised (At home) exercise intervention will incorporate patients' preferred stair and/or walking-based interval exercise (from those completed during hospital trials). Initially patients will complete their chosen protocol three days per week, and then gradually progress exercise load (i.e. reps, work-to-rest ratio, and/or sessions per week) as appropriate, to a maximum of 6 x 60 sec stepping / 5 x 180 sec walking, five times per week (i.e. maximum of ~30 min daily or ~150 min weekly).
Intervention model: Single Group Assignment
Intervention model description: This will be a pragmatic feasibility study of a single case group. However, examination of acute responses to different step and walk-based interval exercise types will follow a randomised, counter-balanced (repeated-measures) design.
Masking: None (Open Label)
Primary purpose: Other