Participant acceptability of exercise in kidney disease (PACE-KD): a feasibility study protocol in renal transplant...

Cardiovascular disease (CVD) is a major cause of mortality in renal transplant recipients (RTRs). General population risk scores for CVD underestimate the risk in patients with chronic kidney disease (CKD) suggesting additional non-traditional factors. Renal transplant recipients also exhibit elevated inflammation and impaired immune function. Exercise has a positive impact on these factors in patients with CKD but there is a lack of rigorous research in RTRs, particularly surrounding the feasibility and acceptability of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) in this population. This study aims to explore the feasibility of three different supervised aerobic exercise programmes in RTRs to guide the design of future large-scale efficacy studies.

Renal transplant recipients will be randomised to HIIT A (16 min interval training with 4, 2 and 1 min intervals at 80%-90% of peak oxygen uptake (VO_{2 peak})), HIIT B (4×4 min interval training at 80%-90% VO_2peak) or MICT (~40 min cycling at 50%-60% VO_2peak) where they will undertake 24 supervised sessions (approximately thrice weekly over 8 weeks). Assessment visits will be at baseline, midtraining, immediate post-training and 3 months post-training. The study will evaluate the feasibility of recruitment, randomisation, retention, assessment procedures and the implementation of the interventions. A further qualitative sub-study QPACE-KD (Qualitative Participant Acceptability of Exercise in Kidney Disease) will explore patient experiences and perspectives through semistructured interviews and focus groups.

All required ethical and regulatory approvals have been obtained. Findings will be disseminated through conference presentations, public platforms and academic publications.

Prospectively registered; ISRCTN17122775.