Title: Feasibility of high intensity interval training in pulmonary rehabilitation programmes for patients with interstitial lung disease and preliminary efficacy of its long-term benefits.
Funder: Department of Health (England)

Abstract: Interstitial lung disease (ILD) is a term used for a diverse group of pulmonary conditions that affect the lung tissue. ILD is classified in different types, including interstitial pulmonary fibrosis (IPF) that has the worse prognosis from all other types [1]. Patients with ILD experience progressive breathlessness, fatigue and poor exercise capacity and enter a vicious cycle of inactivity and physical deconditioning by avoiding activities that increase their symptoms One of the most effective ways to break this cycle is pulmonary rehabilitation (PR) [2]. PR programmes are multidisciplinary programmes of exercise and education that improve muscle function, breathlessness and self-management in ILD. However, the optimal exercise prescription for long term benefits is currently unknown for this patient group [3]. In addition, recent data emerged that showed high intensity training interval training (HIIT) to be feasible and effective in severe ILD patients prior to lung transplantation [4]. HIIT involves repeatedly exercising at a high intensity for 30 seconds to several minutes, followed by 1-5 minutes of recovery (low intensity exercise or no exercise). It has been shown to increase patient compliance and to improve cardiovascular and metabolic outcomes in healthy people and patient groups [5] such as heart failure patients [6], and cancer survivors [7]. HIIT has yet to be studied in pulmonary rehabilitation programmes for ILD. This study aims to investigate the feasibility of HIIT in a pulmonary rehabilitation programme and its long term efficacy in comparison to a moderate intensity continuous training programme (MICT). More specifically, we plan to study the effects of each programme on exercise capacity, breathlessness and health status (health-related quality of life). 60 patients with various types of ILD will be randomised into 2 groups: Group A: PR using MI-CT and Group B: PR using a HIIT programme. Patients will train twice weekly for 8 weeks. The HIIT will be prescribed at >80% VO2max, with the duration of each interval based on each patient’s capacity to keep saturation level (SaO2) above 89%. Assessment of outcomes will take place at the beginning, immediately post-PR and 6 months later. The key questions to be addressed are as follows: What is the relative recruitment of different types of ILD to each programme? What is the retention and adherence of different types of ILD to each programme? Is HIIT equally well tolerated in the various types? What is the efficacy of each programme on exercise capacity in the various types of ILD immediately post-PR programme and 6 months later? Does breathlessness and quality of life improve and are maintained more with an HIIT versus a MICT programme? The results of our study will inform the sample size and other practical issues before designing a definitive trial and will provide evidence about the long term efficacy of HIIT. The results on the efficacy of HIIT, whether positive or negative will allow us to design more focused pulmonary rehabilitation programmes for patients with various types of ILD. We will monitor closely the response of patients with interstitial pulmonary fibrosis (IPF) to our programme, as this type has the worst prognosis amongst all other types of ILD and so far, no other rehabilitation intervention has shown significant changes in physical function or mortality. We will publish the results of this feasibility study and will engage other interested research groups as early as possible. We expect that the definitive study will lead to important changes in the clinical management of ILD patients across the UK and internationally.


Research activity codes: 7.1 INDIVIDUAL CARE NEEDS;6.7 PHYSICAL
Health categories: RESPIRATORY