Background: Whether high-intensity interval training (HIIT) is more efficient than moderate-intensity continuous exercise (MICE) to increase cardiorespiratory fitness in patients with acute coronary syndrome at moderate-to-high cardiovascular risk is controversial. The best approach to guide training intensity remains to be determined.
Objective: We aimed to assess intensities achieved with self-tailored HIIT and MICE according to perceived exertion and to compare the effect on cardiorespiratory fitness in patients early after ST-elevation myocardial infarction (STEMI).
Methods: We included 69 males starting cardiac rehabilitation within 4 weeks after STEMI. After a 3-week run-in phase with MICE, 35 patients were randomized to 9 weeks of HIIT (2×HIIT and 1×MICE per week) and 34 patients to MICE (3×MICE). Training workload for MICE was initially set at the patients’ first ventilatory threshold (VT). HIIT consisted of 4×4-min intervals with a workload above the second VT in high intervals. Training intensity was adjusted weekly to maintain the perceived exertion (Borg score 13-14 for MICE, ≥15 for HIIT). Session duration was 38 min in both groups. Peak oxygen consumption (VO2) was measured by cardiopulmonary exercise testing pre- and post-intervention.
Results: Both groups improved peak VO2 (ml/kg/min) (HIIT +1.9, p<0.001; MICE +3.2, p<0.001, Cohen’s d -0.4), but changes in VO2 were not significantly different between groups (p=0.104). Exercise regimes did not differ between groups in terms of energy expenditure or training time, but perceived exertion was higher with HIIT.
Conclusions: Self-tailored HIIT was feasible in patients early after STEMI. It was more strenuous but not superior nor more time efficient than MICE in improving peak VO2.Le texte complet de cet article est disponible en PDF.
Keywords : exercise capacity, VO2peak, exercise intensity prescription, training modality, cardiac rehabilitation, Borg scale, self-rating