Real-Time HIIT Response in Patients with Coronary Artery Disease: A CERT-Based 1 Report from the Heart-Brain Randomized Controlled Trial

AimsHigh-intensity interval training (HIIT) and resistance training (RT) are promising options for cardiac rehabilitation, yet exercise trials seldom report sufficient protocol details or participants response and experience in a standardised way. We therefore quantified and compared attendance rate, heart-rate-based compliance, perceived exertion, enjoyment and affect during a 12-week programme performed as either HIIT or HIIT plus RT (HIIT + RT). Both interventions were documented according to the Consensus on Exercise Reporting Template (CERT). MethodsA total of 105 patients with coronary artery disease (62 {+/-} 7 years, 78 % men) were randomised to: usual care, HIIT or HIIT + RT. This study focus on the two exercise programs (n=64) consisting on three supervised 45-min sessions per week. Intensity for the high-intensity intervals was prescribed as 85-95 % of peak heart rate (HRpeak) and monitored both objectively in real time (second-by-second) and subjectively (Borg 0-10 Rating of Perceived Exertion scale). Outcomes were (i) attendance (sessions attended / sessions offered), (ii) intensity compliance (proportion of sessions meeting intensity target), (iii) enjoyment (Physical Activity Enjoyment Scale, 1-7) and (iv) affect response (Feeling Scale, -5 to +5 pre- and post-exercise). ResultsParticipants attended 88 % of scheduled sessions (HIIT 85 %, HIIT + RT 90 %; p=0.46) and were compliant with the prescribed heart rate intensity zone in an average of 75% of the attended sessions (HIIT 72%, HIIT+RT 78%; p = 0.48). Enjoyment was similarly high in both groups (overall PACES 5.4 / 7). Mean RPE during high-intensity intervals was 7.1 / 10 for both groups; in HIIT + RT, average RPE during resistance circuits were 5.1. Feeling-Scale scores improved after exercise sessions in both programs (HIIT +0.65; HIIT + RT +0.45), with a statistically significant advantage for HIIT+RT in post-session affective response, after adjusting for pre-session scores (p < .001) ConclusionOur HIIT and HIIT + RT programs resulted in high attendance and compliance, and were positively experienced by patients with coronary artery disease, providing a feasible and time-efficient alternative for meeting international exercise guidelines (including RT). The fully CERT-documented protocols offer a reproducible research and clinical work.