Effects of interval cycle training with or without strength training on vascular reactivity in heart failure patients

Abstract

Background: Exercise training confers beneficial effects on vascular reactivity in patients with chronic heart failure (CHF). This randomized study compares the effects of interval cycle training combined with strength training versus interval training alone on vascular reactivity in CHF patients.

Methods: Twenty-eight consecutive stable CHF patients (23 males, 53 ± 10 years, 28.4 ± 4.1 kg/m(2), left ventricular ejection fraction of 37 ± 12%) were randomly assigned to 3 times' weekly training sessions for 3 months, consisting of a) 40 minutes of interval cycle training (n = 14), versus b) 20 minutes of similar interval training plus 20 minutes of strength training of the quadriceps, hamstrings, muscles of the shoulder and biceps brachialis (n = 14). The work/recovery ratio of each session was 30/60 seconds. The intensity of interval training was set at 50% of the peak workload achieved at the steep ramp test (consisted of a 25-Watt increase on a cycle ergometer every 10 seconds until exhaustion). All patients underwent maximal, symptom-limited cardiopulmonary exercise testing and ultrasound evaluation of vascular reactivity by flow-mediated vasodilation (FMD) before and after the program.

Results: A significant improvement in FMD was observed in the combined training group (P = 0.002), in contrast to the interval training alone group (P = NS); the improvement was significantly greater in the combined training than in the interval training alone group (P < .05). Peak oxygen uptake increased significantly and similarly in both groups, in the interval training group (P = .03), and in the combined training group (P = .006). No significant correlation was found between FMD improvement and cardiopulmonary exercise parameters.

Conclusions: A combined high-intensity, interval cycle exercise with strength training induces a greater beneficial effect on vascular reactivity rather than interval exercise training alone in CHF patients.