High-intensity interval training dose and cardiorespiratory fitness in coronary artery disease: a systematic review and dose-response meta-analysis.

Abstract

To quantify the impact of high-intensity interval training (HIIT) on cardiorespiratory fitness (VO₂max) in patients with coronary artery disease (CAD) and to explore the dose-response relationship. We conducted a systematic review and Bayesian meta-analysis of randomized controlled trials (RCTs), searching PubMed, Embase, Cochrane Library, and Web of Science databases. Study quality was assessed using the Cochrane Risk of Bias Tool. Data were analyzed using a random-effects model and meta-regression. Thirteen RCTs involving 833 patients were included. Meta-analysis demonstrated that HIIT significantly improved VO₂max compared to controls (mean difference [MD] = 3.20 mL/kg/min; 95% credible interval [CrI]: 2.78-3.61). Dose-response analysis revealed a nonlinear relationship, with the minimum effective dose identified at approximately 620 MET-min/week. Baseline VO₂max, age, and gender did not significantly moderate the effects of HIIT. HIIT effectively improves cardiorespiratory fitness in CAD patients, with consistent benefits across various baseline fitness levels. The identified optimal dose (approximately 620 MET-min/week) supports personalized exercise prescription, particularly for populations with motivational or time-related barriers to sustained exercise adherence.