Extracorporeal Shockwave for Intermittent Claudication and Quality of Life: A Randomized Clinical Trial.

Importance: Intermittent lower limb claudication limits function and quality of life. Supervised exercise programs are not readily available, and a noninvasive alternative is needed. Objective: To assess extracorporeal corporeal shockwave therapy in improving quality of life in patients with claudication. Design, Setting, and Participants: In this double-blind, placebo-controlled randomized clinical trial, patients in the outpatient setting at a single tertiary center for vascular surgery were randomized in a 1:1 ratio to extracorporeal shockwave therapy or placebo therapy with no shockwaves delivered. Recruitment was between June 2015 and January 2020, with 12-week follow-up ending in March 2020. A convenience sample of patients with claudication and conservative treatment requirements who refused or were unable to participate in supervised exercise were eligible. Patients receiving anticoagulation therapy or with an active cancer were excluded. Of 522 patients screened, 389 were eligible, 138 were enrolled, and 110 completed follow-up and were included in the primary analysis. Statistical analysis was completed by May 2021. Intervention: In the intervention group, patients received 100 impulses of 0.1mJ/mm/cm2 in an area of the gastrocnemius muscle 3 times weekly for 3 weeks. The steps for treatment were replicated for the control group without delivering the treatment. Main Outcomes and Measures: The primary outcome was the Physical Functioning domain of the 36-item Short-Form Quality of Life Questionnaire at 12-week follow-up. Secondary outcomes included walking distances, ankle brachial pressure index, and other quality-of-life measures. Results: Of 138 patients recruited and randomized, 92 (67%) were male, and the mean (SD) age of the study population was 67 (9.6) years. The intervention group had a significantly higher physical function score at 12 weeks (estimated median difference 3.8; 95% CI, 0.0-7.7; P = .03). However, this significance did not remain when adjusting for covariates. At 12 weeks, the intervention group had significantly longer pain-free and maximum walking distances (pain-free estimated median difference, 34.1, 95% CI, 11.4-56.8; P = .004; maximum estimated median difference, 51.4; 95% CI, 10.7-86.5; P = .01). Conclusions and Relevance: To our knowledge, this is the first double-blind, placebo-controlled, randomized clinical trial to consider extracorporeal shockwave therapy for the management of intermittent claudication. It demonstrated efficacy for walking distances, may have a positive effect on quality of life, and may provide a safe, noninvasive alternative therapy for patients with intermittent claudication. Trial Registration: ClinicalTrials.gov Identifier: NCT02652078.

Supported exercise TrAining for Men wIth prostate caNcer on Androgen deprivation therapy (STAMINA): study protocol for a randomised controlled trial of the clinical and cost-effectiveness of the STAMINA lifestyle intervention compared with optimised usual care, including internal pilot and parallel process evaluation.

BACKGROUND: UK national clinical guidance recommends that men with prostate cancer on androgen deprivation therapy are offered twice weekly supervised aerobic and resistance exercise to address iatrogenic harm caused by treatment. Very few NHS trusts have established adequate provision of such services. Furthermore, interventions fail to demonstrate sustained behaviour change. The STAMINA lifestyle intervention offers a system-level change to clinical care delivery addressing barriers to long-term behaviour change and implementation of new prostate cancer care pathways. This trial aims to establish whether STAMINA is clinically and cost-effective in improving cancer-specific quality of life and/or reducing fatigue compared to optimised usual care. The process evaluation aims to inform the interpretation of results and, if the intervention is shown to benefit patients, to inform the implementation of the intervention into the NHS. METHODS: Men with prostate cancer on androgen deprivation therapy (n = 697) will be identified from a minimum of 12 UK NHS trusts to participate in a multi-centre, two-arm, individually randomised controlled trial. Consenting men will have a 'safety to exercise' check and be randomly allocated (5:4) to the STAMINA lifestyle intervention (n = 384) or optimised usual care (n = 313). Outcomes will be collected at baseline, 3-, 6- and 12-month post-randomisation. The two primary outcomes are cancer-specific quality of life and fatigue. The parallel process evaluation will follow a mixed-methods approach to explore recruitment and aspects of the intervention including, reach, fidelity, acceptability, and implementation. An economic evaluation will estimate the cost-effectiveness of the STAMINA lifestyle intervention versus optimised usual care and a discrete choice experiment will explore patient preferences. DISCUSSION: The STAMINA lifestyle intervention has the potential to improve quality of life and reduce fatigue in men on androgen deprivation therapy for prostate cancer. Embedding supervised exercise into prostate cancer care may also support long-term positive behaviour change and reduce adverse events caused by treatment. Findings will inform future clinical care and could provide a blueprint for the integration of supervised exercise and behavioural support into other cancer and/or clinical services. TRIAL REGISTRATION: ISRCTN 46385239, registered on 30/07/2020. Cancer Research UK 17002, retrospectively registered on 24/08/2022.

High INtensity Interval Training in pATiEnts with Intermittent Claudication: A Qualitative Acceptability Study.

BACKGROUND: A novel high-intensity interval training (HIIT) program has demonstrated feasibility for patients with intermittent claudication (IC). The aim of this study was to explore patient perspectives of the HIIT program to inform refinement and future research. METHODS: All patients screened and eligible for the 'high intensity interval training in patients with intermittent claudication (INITIATE)' study were eligible to take part in a semistructured interview. A convenience subsample of patients was selected from 3 distinct groups: 1) those who completed the HIIT program, 2) those who prematurely discontinued the HIIT program, and 3) those who declined the HIIT program. Interviews considered patients views of the program and experiences of undertaking and/or being invited to undertake it. Interviews were audio recorded, transcribed verbatim, and analyzed via thematic analysis. RESULTS: Eleven out of 31 participants who completed the program and 12 out of 38 decliners were interviewed. No participants who withdrew from the program agreed to interview. The 3 key themes were; personal reflections of the program; program facilitators and barriers; and perceived benefits. Completers enjoyed taking part, reported symptomatic improvement and would complete it again. Practical and psychological barriers exist, such as transport and motivation. Changes to the program were suggested. CONCLUSIONS: Findings support the acceptability of this novel HIIT program, which in combination with the feasibility findings, suggest that a fully powered randomized controlled trial, comparing HIIT to usual-care supervised exercise programs is warranted.

A preoperative supervised exercise program potentially improves long-term survival after elective abdominal aortic aneurysm repair.

OBJECTIVE: A preoperative supervised exercise program (SEP) improves cardiorespiratory fitness and perioperative outcomes for patients undergoing elective abdominal aortic aneurysm (AAA) repair. The aim of this study was to assess the effect of a preoperative SEP on long-term survival of these patients. A secondary aim was to consider long-term changes in cardiorespiratory fitness and quality of life. METHODS: Patients scheduled for open or endovascular AAA repair were previously randomized to either a 6-week preoperative SEP or standard management, and a significant improvement in a composite outcome of cardiac, pulmonary, and renal complications was seen following SEP. For the current analysis, patients were followed up to 5 years post-surgery. The primary outcome for this analysis was all-cause mortality. Data were analyzed on an intention to treat (ITT) and per protocol (PP) basis, with the latter meaning that patients randomized to SEP who did not attend any sessions were excluded. The PP analysis was further interrogated using a complier average causal effect (CACE) analysis on an all or nothing scale, which adjusts for compliance. Additionally, patients who agreed to follow-up attended the research center for cardiopulmonary exercise testing and/or provided quality of life measures. RESULTS: ITT analysis demonstrated that the primary endpoint occurred in 24 of the 124 participants at 5 years, with eight in the SEP group and 16 in the control group (P = .08). The PP analysis demonstrated a significant survival benefit associated with SEP attendance (4 vs 16 deaths; P = .01). CACE analysis confirmed a significant intervention effect (hazard ratio, 0.36; 95% confidence interval, 0.16-0.90; P = .02). There was no difference between groups for cardiorespiratory fitness measures and most quality of life measures. CONCLUSIONS: These novel findings suggest a long-term mortality benefit for patients attending a SEP prior to elective AAA repair. The underlying mechanism remains unknown, and this merits further investigation.

High-intensity interval training in patients with intermittent claudication.

OBJECTIVE: Provision, uptake, adherence, and completion rates for supervised exercise programs (SEP) for intermittent claudication (IC) are low. A shorter, more time-efficient, 6-week, high-intensity interval training (HIIT) program may be an effective alternative that is more acceptable to patients and easier to deliver. The aim of this study was to determine the feasibility of HIIT for patients with IC. METHODS: A single arm proof-of-concept study, performed in secondary care, recruiting patients with IC referred to usual-care SEPs. Supervised HIIT was performed three times per week for 6 weeks. The primary outcome was feasibility and tolerability. Potential efficacy and potential safety were considered, and an integrated qualitative study was undertaken to consider acceptability. RESULTS: A total of 280 patients were screened: 165 (59%) were eligible, and 40 (25%) were recruited. The majority (n = 31; 78%) of participants completed the HIIT program. The remaining nine patients were withdrawn or chose to withdraw. Completers attended 99% of training sessions, completed 85% of sessions in full, and performed 84% of completed intervals at the required intensity. There were no related serious adverse events. Maximum walking distance (+94 m; 95% confidence interval, 66.6-120.8 m) and the SF-36 physical component summary (+2.2; 95% confidence interval, 0.3-4.1) were improved following completion of the program. CONCLUSIONS: Uptake to HIIT was comparable to SEPs in patients with IC, but completion rates were higher. HIIT appears feasible, tolerable, and potentially safe and beneficial for patients with IC. It may provide a more readily deliverable, acceptable form of SEP. Research comparing HIIT with usual-care SEPs appears warranted.

A systematic review of exercise intervention reporting quality and dose in studies of intermittent claudication.

BACKGROUND: Exercise therapy is an important treatment option for people with intermittent claudication (IC). Appropriate reporting of exercise interventions in populations with IC within randomised controlled trials (RCTs) is important to ensure that research can be translated into clinical practice. Therefore, the purpose of our review is to evaluate the reporting of exercise interventions in RCTs of exercise therapy in patients with IC. METHODS: A systematic search was performed to identify relevant trials in patients with IC published until May 2020. Studies including only participants with critical limb ischaemia or asymptomatic peripheral artery disease were excluded. Each trial was scored using the recently developed 'Consensus on Exercise Reporting Template' (CERT) which has a maximum obtainable score of 19. RESULTS: Of 1489 unique records identified from the search, 73 trials were included, reporting 107 exercise interventions. Overall, the average CERT score was 10/19. The exercise equipment used, the use of supervision and a description of whether the exercise prescription was tailored or generic were the most frequently reported intervention components. The motivational strategies used, intervention adherence and intervention fidelity were the most underreported CERT components. There was no trend indicating that CERT scores were higher in more recent publications. CONCLUSIONS: We have identified that important details about exercise interventions are frequently missing from the published literature. These missing data hinder replication of research findings and limit the translation of evidence into clinical practice.

The Edinburgh Claudication Questionnaire has poor diagnostic accuracy in people with intermittent claudication.

BACKGROUND: The screening and diagnosis of intermittent claudication is a challenging process and often relies on the expertise of specialist vascular clinicians. We sought to investigate the diagnostic performance of the Edinburgh Claudication Questionnaire (ECQ) as a screening tool for referrals of suspected intermittent claudication from primary to secondary care. METHOD: Prospectively, 100 referrals from primary care with a stated diagnosis or query regarding intermittent claudication were recruited. All participants who completed the ECQ, underwent an anklebrachial pressure index (ABPI) assessment and treadmill exercise testing. Outcomes of the ECQ were compared to clinical diagnoses of intermittent claudication. RESULTS: The ECQ had a sensitivity of 46.8% (95% CI: 27-65%), specificity of 63.2% (95% CI: 43-82%) and accuracy of 53.0% (95% CI: 43-63%). The diagnostic performance was not changed by combining the ECQ with a positive ABPI or post-exercise ABPI outcome for PAD. CONCLUSION: The ECQ had a poor diagnostic performance in this cohort. Considering the results found here and in other recent studies, the utility of the ECQ as a screening tool and epidemiological survey tool must be questioned. Novel, low-resource diagnostic tools are needed in this population.

Provision of exercise services in patients with peripheral artery disease in the United Kingdom.

OBJECTIVES: Supervised exercise programmes (SEPs) are a vital treatment for people with intermittent claudication, leading improvements in walking distance and quality of life and are recommended in multiple national and international guidelines. We aimed to evaluate the use and structure of SEPs in the United Kingdom (UK). DESIGN: We conducted an anonymous online survey using the Jisc platform comprising of 40 questions. The survey was designed to address key areas such as access, provision, uptake and delivery of SEPs in the United Kingdom. Ethical approval was obtained from Coventry University (P108729). METHODS: The list of trusts providing vascular services was obtained from the National Vascular Registry (NVR) report. The survey was disseminated via social media, The Vascular Society of Great Britain and Ireland and the Society for Vascular Technology. Data were exported to a Microsoft Excel document and analysed using simple descriptive statistics. RESULTS: Of 93 vascular units identified, we received response from 48. Of these, 23 had access to an exercise programme (48%). The majority of SEPs were exclusively for PAD patients (77%), with 21% using integrated services. 67% of respondents were providing a circuit-based programme, and 5 out of 23 were meeting the dose recommendations in the UK National Institute for Health and Care Excellence (NICE) guidelines. Respondents felt that programmes were moderately to extremely important to patients, slightly to very important to clinicians and not at all important to slightly important to commissioning/funding bodies. CONCLUSION: SEPs are a well-established first-line treatment for patients with IC and they are recommended by NICE guidelines. Despite this, many patients still do not have access to an exercise programme, and clinicians do not feel that they have support from commissioning/funding bodies to develop them. There is an urgent need for funding, development and delivery of SEPs in the United Kingdom.

An updated systematic review and meta-analysis of home-based exercise programs for individuals with intermittent claudication.

OBJECTIVE: Supervised exercise programs (SEP) are effective for improving walking distance in patients with intermittent claudication (IC) but provision and uptake rates are suboptimal. Access to such programs has also been halted by the Coronavirus pandemic. The aim of this review is to provide a comprehensive overview of the evidence for home-based exercise programs (HEP). METHODS: This review was conducted in according with the published protocol and PRISMA guidance. Medline, EMBASE, CINAHL, PEDro, and Cochrane CENTRAL were searched for terms relating to HEP and IC. Randomized and nonrandomized trials that compared HEP with SEP, basic exercise advice, or no exercise controls for IC were included. A narrative synthesis was provided for all studies and meta-analyses conducted using data from randomized trials. The primary outcome was maximal walking distance. Subgroup analyses were performed to consider the effect of monitoring. Risk of bias was assessed using the Cochrane tool and quality of evidence via GRADE. RESULTS: We included 23 studies with 1907 participants. Considering the narrative review, HEPs were inferior to SEPs which was reflected in the meta-analysis (mean distance [MD], 139 m; 95% confidence interval [CI], 45-232 m; P = .004; very low quality of evidence). Monitoring was an important component, because HEPs adopting this strategy were equivalent to SEPs (MD, 8 m; 95% CI, -81 to 97; P = .86; moderate quality of evidence). For HEPs vs basic exercise advice, narrative review suggested HEPs can be superior, although not always significantly so. For HEPs vs no exercise controls, narrative review and meta-analysis suggested HEPs were potentially superior (MD, 136 m; 95% CI, -2 to 273 m; P = .05; very low quality of evidence). Monitoring was also a key element in these comparisons. Other elements such as appropriate frequency (≥3× a week), intensity (to moderate-maximum pain), duration (20 progressing to 60 minutes) and type (walking) of exercise were important, as was education, self-regulation, goal setting, feedback, and action planning. CONCLUSIONS: When SEPs are unavailable, HEPs are recommended. However, to elicit maximum benefit they should be structured, incorporating all elements of our evidence-based recommendations.

Embedding supervised exercise training for men on androgen deprivation therapy into standard prostate cancer care: a feasibility and acceptability study (the STAMINA trial).

Lifestyle interventions involving exercise training offset the adverse effects of androgen deprivation therapy in men with prostate cancer. Yet provision of integrated exercise pathways in cancer care is sparse. This study assessed the feasibility and acceptability of an embedded supervised exercise training intervention into standard prostate cancer care in a single-arm, multicentre prospective cohort study. Feasibility included recruitment, retention, adherence, fidelity and safety. Acceptability of behaviourally informed healthcare and exercise professional training was assessed qualitatively. Despite the imposition of lockdown for the COVID-19 pandemic, referral rates into and adherence to, the intervention was high. Of the 45 men eligible for participation, 79% (n = 36) received the intervention and 47% (n = 21) completed the intervention before a government mandated national lockdown was enforced in the United Kingdom. Patients completed a mean of 27 min of aerobic exercise per session (SD = 3.48), at 77% heart rate maximum (92% of target dose), and 3 sets of 10 reps of 3 resistance exercises twice weekly for 12 weeks, without serious adverse event. The intervention was delivered by 26 healthcare professionals and 16 exercise trainers with moderate to high fidelity, and the intervention was deemed highly acceptable to patients. The impact of societal changes due to the pandemic on the delivery of this face-to-face intervention remain uncertain but positive impacts of embedding exercise provision into prostate cancer care warrant long-term investigation.

A systematic review of exercise testing in patients with intermittent claudication: A focus on test standardisation and reporting quality in randomised controlled trials of exercise interventions.

A systematic review was conducted to identify the range of terminology used in studies to describe maximum walking distance and the exercise testing protocols, and testing modalities used to measure it in patients with intermittent claudication. A secondary aim was to assess the implementation and reporting of the exercise testing protocols. CINAHL, Medline, EMBASE and Cochrane CENTRAL databases were searched. Randomised controlled trials whereby patients with intermittent claudication were randomised to an exercise intervention were included. The terminology used to describe maximal walking distance was recorded, as was the modality and protocol used to measure it. The implementation and reporting quality was also assessed using pre-specified criteria. Sixty-four trials were included in this review. Maximal walking distance was reported using fourteen different terminologies. Twenty-two different treadmill protocols and three different corridor tests were employed to assess maximal walking distance. No single trial satisfied all the implementation and reporting criteria for an exercise testing protocol. Evidence shows that between-study interpretation is difficult given the heterogenous nature of the exercise testing protocols, test endpoints and terminology used to describe maximal walking distance. This is further compounded by poor test reporting and implementation across studies. Comprehensive guidelines need to be provided to enable a standardised approach to exercise testing in patients with intermittent claudication.

Remote interventions to improve exercise behaviour in sedentary people living with and beyond cancer: a systematic review and meta-analysis.

BACKGROUND: The COVID-19 pandemic has forced many cancer services to consider a transition to a remote format of delivery that is largely untested. Accordingly, we sought to perform a systematic review of the effects of remotely delivered interventions to improve exercise behaviour in sedentary adults living with and beyond cancer. METHODS: Eligible studies were randomised controlled trials comparing a remotely delivered exercise intervention to a usual care comparison in sedentary people over 18 years old with a primary cancer diagnosis. Nine electronic databases were searched from inception to November 2020. RESULTS: The review included three trials, totalling 186 participants. Two of the included trials incorporated prescriptions that meet current aerobic exercise recommendations, one of which also meets the guidelines for resistance exercise. No trials reported an intervention adherence of 75% or more for a set prescription that meets current exercise guidelines. CONCLUSION: There is little evidence suggesting that remote exercise interventions promote exercise behaviours or improve physical function in sedentary adults living with and beyond cancer. The development and evaluation of novel remote exercise interventions is needed to establish their usefulness for clinical practice. Given the social response to the COVID-19 pandemic, further research in this area is urgently needed.

Considering the Feasibility, Tolerability, and Safety of High-Intensity Interval Training as a Novel Treatment for Patients With Intermittent Claudication.

PURPOSE: This study assessed the feasibility, tolerability, safety, and potential efficacy of a novel, 6-wk, high-intensity interval training (HIIT) program for patients with intermittent claudication (IC). METHODS: Patients referred to a usual-care supervised exercise program were invited to undertake a HIIT program. All recruited patients performed a baseline cardiopulmonary exercise test (CPX) to inform their exercise prescription. HIIT involved 10, 1-min high-intensity cycling intervals interspersed with 1-min recovery intervals, performed 3 d/wk for 6 wk. Outcomes included feasibility, tolerability, safety, walking distance, and quality of life. RESULTS: A total of 144 patients with IC were referred, 95 met initial eligibility criteria (66%) and 30 (32%) were recruited for HIIT, of which 15 (50%) completed. Of the recruited patients, 90% were on optimal medical therapy and 40% had concomitant cardiac, cerebrovascular, and/or respiratory disease. Patients who completed the program attended 100% of the sessions and one serious adverse event was recorded. Improvements in walking distances and quality of life were observed. Following recruitment of the first 20 patients, the inclusion criteria were refined on the basis of CPX, leading to improved completion rates. CONCLUSIONS: This study provides preliminary findings indicating that patients with IC can complete a short-term HIIT program. We provide very early evidence that HIIT may be safe and well-tolerated. In addition, walking distances seem to improve following HIIT. After a small change in the exclusion criteria, the intervention and inclusion/exclusion criteria now seem appropriate for this population, meaning further research to evaluate HIIT in patients with IC is warranted.

UK cardiac rehabilitation fit for purpose? A community-based observational cohort study.

OBJECTIVES: This study aimed to characterise the exercise performed in UK cardiac rehabilitation (CR) and explore relationships between exercise dose and changes in physiological variables. DESIGN: Observational cohort study. SETTING: Outpatient community-based CR in Leeds, UK. Rehabilitation sessions were provided twice per week for 6 weeks. PARTICIPANTS: Sixty patients (45 male/15 female 33-86 years) were recruited following referral to local outpatient CR. OUTCOME MEASURES: The primary outcome was heart rate achieved during exercise sessions. Secondary outcomes were measured before and after CR and included incremental shuttle walk test (ISWT) distance and speed, blood pressure, brachial artery flow-mediated dilatation, carotid arterial stiffness and accelerometer-derived habitual physical activity behaviours. RESULTS: The mean % of heart rate reserve patients exercised at was low and variable at the start of CR (42%±16 %) and did not progress by the middle (48%±17 %) or end (48%±16 %) of the programme. ISWT performance increased following CR (440±150 m vs 633±217 m, p<0.001); however, blood pressure, body weight, endothelial function, arterial stiffness and habitual physical activity behaviours were unchanged following 6 weeks of CR (p>0.05). CONCLUSION: Patients in a UK CR cohort exercise at intensities that are variable but generally low. The exercise dose achieved using this CR format appears inadequate to impact markers of health. Attending CR had no effect on physical activity behaviours. Strategies to increase the dose of exercise patients achieve during CR and influence habitual physical activity behaviours may enhance the effectiveness of UK CR.

Feasibility and reproducibility of a cardiovascular magnetic resonance free-breathing, multi-shot, navigated image acquisition technique for ventricular volume quantification during continuous exercise.

BACKGROUND: Cardiovascular magnetic resonance (CMR) image acquisition techniques during exercise typically requires either transient cessation of exercise or complex post-processing, potentially compromising clinical utility. We evaluated the feasibility and reproducibility of a navigated image acquisition method for ventricular volumes assessment during continuous physical exercise. METHODS: Ten healthy volunteers underwent supine cycle ergometer (Lode) exercise CMR on two separate occasions using a free-breathing, multi-shot, navigated, balanced steady-state free precession cine pulse sequence. Images were acquired at 3-stages, baseline and during steady-state exercise at 55% and 75% maximal heart rate (HRmax), based on a prior supine cardiopulmonary exercise test. Intra-and inter-observer variability and inter-scan reproducibility were derived. Clinical feasibility was tested in a separate cohort of patients with severe mitral regurgitation (n=6). RESULTS: End-diastolic volume (EDV) of both LV and RV decreased during exercise at 55% and 75% HRmax, although a reduction in RVEDV index was only observed at 75% HRmax. Ejection fractions (EF) for both ventricles were significantly higher at 75% HRmax compared to their respective baselines (LVEF 68%±3% vs. 58%±5%, P=0.001; RVEF 66%±4% vs. 58%±7%, P=0.02). Intra-observer and inter-observer reproducibility of LV parameters was excellent at all 3-stages. Although measurements of RVESV were more variable during exercise, the reproducibility of both RVEF and RV cardiac index was excellent (CV <10%). Inter-scan LV and RV ejection fraction were highly reproducible at all 3 stages, although inter-scan reproducibility of indexed RVESV was only moderate. The protocol was well tolerated by all patients. CONCLUSIONS: Exercise CMR using a free-breathing, multi-shot, navigated cine imaging method allows simultaneous assessment of left and right ventricular volumes during continuous exercise. Intra- and inter-observer reproducibility were excellent. Inter-scan LV and RV ejection fraction were also highly reproducible.

High INtensity Interval Training In pATiEnts with intermittent claudication (INITIATE): protocol for a multicentre, proof-of-concept, prospective interventional study.

INTRODUCTION: The first-line recommended treatment for patients with intermittent claudication (IC) is a supervised exercise programme (SEP), which includes a minimum of 2-hours of exercise per week over a 12-week period. However, provision, uptake and adherence rates for these SEP programmes are poor, with time constraints cited as a common participant barrier. High-intensity interval training (HIIT) is more time-efficient and therefore has the potential to overcome this barrier. However, evidence is lacking for the role of HIIT in those with IC. This proof-of-concept study aims to consider the safety, feasibility, tolerability and acceptability of a HIIT programme for patients with IC. METHODS AND ANALYSIS: This multicentre, single-group, prospective, interventional feasibility study will recruit 40 patients with IC, who will complete 6 weeks of HIIT, 3 times a week. HIIT will involve a supervised programme of 10×1 min high-intensity cycling intervals at 85%-90% peak power output (PPO), interspaced with 10×1 min low intensity intervals at 20%-25% PPO. PPO will be determined from a baseline cardiopulmonary exercise test (CPET) and it is intended that patients will achieve ≥85% of maximum heart rate from CPET, by the end of the second HIIT interval. Primary outcome measures are safety (occurrence of adverse events directly related to the study), programme feasibility (including participant eligibility, recruitment and completion rates) and HIIT tolerability (ability to achieve and maintain the required intensity). Secondary outcomes include patient acceptability, walking distance, CPET cardiorespiratory fitness measures and quality of life outcomes. ETHICS AND DISSEMINATION: Ethical approval was obtained via a local National Health Service research ethics committee (Bradford Leeds - 18/YH/0112) and recruitment began in August 2019 and will be completed in October 2020. Results will be published in peer-reviewed journals and presented at international conferences and are expected to inform a future pilot randomised controlled trial of HIIT versus usual-care SEPs. TRIAL REGISTRATION NUMBER: NCT04042311; Pre-results.