Background: The Post Ischaemic Stroke Cardiovascular Exercise Study – Zoom Delivered Intervention against Cognitive Decline (PISCES-ZODIAC) randomised controlled trial compared cardiorespiratory exercise (CRX) with a balance and stretching active control (CON) for effects on hippocampal volume and cognition. Intervention protocol fidelity, including session attendance and intensity targets, remains to be examined.
Aims: To examine fidelity (sessions attended and exercise intensity) of in-person (PISCES) versus home-delivered (ZODIAC) exercise interventions.
Methods: Adults with ischaemic stroke, without cognitive disorders or comorbidities precluding exercise, were randomised two months post-stroke to CRX or CON, completing three 60-minute sessions/week for eight weeks (24 sessions). Fidelity was defined as ≥80% attendance and compliance with prescribed intensity (mean % heart rate reserve [HRR]) and volume. Session fidelity was reported as the number and proportion of sessions achieving the target HRR range.
Results: Of 104 participants (PISCES n=34: CRX=15, CON=19; ZODIAC n=70: CRX=34, CON=36). Few sessions were missed: PISCES CRX 20±7 (83%), CON 21±6 (88%); ZODIAC CRX 19±5 (79%), CON 20±4 (83%). Of 957 CRX sessions (PISCES=298; ZODIAC=659) delivered, 60% met or exceeded exercise intensity targets (PISCES=207, 70%; ZODIAC=365, 55%). Of 1128 CON sessions (PISCES=407; ZODIAC=721), 88% were within target (<40% HRR). Time constraints (i.e., adhering to 60-minute session) was the most common barrier to protocol adherence.
Conclusions: Stroke survivors demonstrated acceptable fidelity across both delivery modes. Variability was driven primarily by time constraints, highlighting the importance of structured intervention monitoring and adaptive feedback to support protocol adherence supporting translation into scalable, high-quality real-world stroke rehabilitation practice.