Matched dose interval and continuous exercise training induce similar cardiorespiratory and metabolic adaptations in patients with heart failure

Background: The best format of exercise training in patients with chronic heart failure (CHF) is controversial. We tested the hypothesis that aerobic continuous training (ACT) and aerobic interval training (AIT) induce similar effects on functional capacity, central hemodynamics and metabolic profile in patients with postinfarction CHF provided that the training load is equated by an individually-tailored volume/intensity dose of exercise.

Methods: Twenty patients with postinfarction CHF under optimal medical treatment were randomized to ACT or AIT for 12 weeks. Exercise training consisted in individualized loads prescribed according to the Training Impulses (TRIMPi) method, which was determined using the individual HR and lactate profiling obtained during a treadmill test at baseline.

Results: Peak VO2 increased significantly by 22% with both ACT and AIT, without differences between the two training programs. Changes in anaerobic threshold and VE/VCO2 slope were not significantly different between ACT and AIT. Resting HR significantly decreased with both exercise modes. Resting cardiac output and stroke volume, left ventricular diastolic dimension and ejection fraction did not change from baseline with both exercise modes. Lipid profile and glucose metabolism were not substantially altered by ACT and AIT.

Conclusions: ACT and AIT both induce significant improvement in aerobic capacity in patients with postinfarction CHF, without significant differences between the two training modes, provided that patients are trained at the same, individually tailored, dose of exercise. The TRIMPi method might represent a step forward in the individualization of an aerobic training tailored to the patient's clinical and functional status within cardiac rehabilitation programs.