title: Feasibility of high-intensity interval training and moderate-intensity continuous training in adults with inactive or mildly active Crohn's disease: study protocol for a randomised controlled trial.
abstract: BACKGROUND
  Structured exercise training has been proposed as a useful adjunctive therapy for Crohn's disease by improving immune function and psychological health, reducing fatigue and promoting gains in muscle and bone strength. However, the evidence for exercise in Crohn's disease is sparse, with only a handful of small prospective trials [1, 2], with methodological limitations, including the use of non-randomised and non-controlled study designs and small sample sizes. Here, we describe the protocol for a study that aims to assess the feasibility and acceptability of two common types of exercise training-high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT)-in adults with inactive or mildly active Crohn's disease (CD).
  
  
  METHODS
  This is a randomised, controlled, assessor-blinded, feasibility trial with three parallel groups. Forty-five adults with inactive or mildly active Crohn's disease will be randomly assigned 1:1:1 to HIIT, MICT or usual care control. Participants in the HIIT and MICT groups will be invited to undertake three sessions of supervised exercise each week for 12 consecutive weeks. HIIT sessions will consist of ten 1-min intervals of cycling exercise at 90% of peak power output separated by 1 min of active recovery. MICT sessions will involve 30 min of continuous cycling at 35% of peak power output. Participants will be assessed before randomisation and 13 and 26 weeks after randomisation. Feasibility outcomes include rates of recruitment, retention and adherence. Interviews with participants will explore the acceptability of the exercise programmes and study procedures. Clinical/health outcomes include cardiorespiratory fitness, body mass index, resting blood pressure, markers of disease activity (faecal calprotectin and Crohn's Disease Activity Index) and activated T cell cytokine profiles. Study questionnaires include the Inflammatory Bowel Disease Quality of Life Questionnaire, EQ-5D-5L, IBD Fatigue Scale, Hospital and Anxiety Depression Scale, and International Physical Activity Questionnaire.
  
  
  CONCLUSIONS
  This study will provide useful information on the feasibility and acceptability of supervised exercise training in adults with inactive and mildly active Crohn's disease and will inform the design of a subsequent, adequately powered, multi-centre trial.
  
  
  BACKGROUND
  The trial is registered with the International Standard Randomised Controlled Trial Register (ISRCTN13021107). Date registration assigned was 02/12/2015.
authors.affiliation: Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle, NE1 8ST UK.
authors.forename: Garry A
authors.initials: GA
authors.lastname: Tew
authors.affiliation: School of Health, Sport and Bioscience, University of East London, Stratford Campus, London, E15 4LZ UK.
authors.forename: Roger
authors.initials: R
authors.lastname: Carpenter
authors.affiliation: School of Health, Sport and Bioscience, University of East London, Stratford Campus, London, E15 4LZ UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Seed
authors.affiliation: Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Anderson
authors.affiliation: Digestive Diseases Clinical Academic Unit, Barts and the London NHS Trust, London, UK.
authors.forename: Louise
authors.initials: L
authors.lastname: Langmead
authors.affiliation: York Trials Unit, University of York, Heslington, York YO10 5DD UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Fairhurst
authors.affiliation: Centre for Psychology and Sports Science, Life and Medical Sciences, University of Hertfordshire, CP Snow Building, College Lane, Hatfield, AL10 9AB UK.
authors.forename: Lindsay
authors.identifier: 0000-0003-4632-3764
authors.initials: L
authors.lastname: Bottoms
keywords: Crohn’s disease; Exercise therapy; Feasibility studies; Inflammatory bowel disease; Physical therapy; Randomised controlled trial; Rehabilitation