Cardiac rehabilitation in chronic heart failure: effect of an 8-week, high-intensity interval training versus continuous training.

OBJECTIVE: To compare the effects of an 8-week, high-intensity interval training protocol versus continuous training. DESIGN: Randomized controlled trial. SETTING: Cardiac rehabilitation center. PARTICIPANTS: Patients (N=26; mean age ± SD, 54±12y) with chronic heart failure were enrolled in a cardiac rehabilitation program for 8 weeks. INTERVENTIONS: Patients were randomly assigned into 2 groups that performed either interval training (IT) or continuous training (CT). IT consisted of 3 sessions of 12 repetitions of 30 seconds of exercise at very high intensity, followed by 60 seconds of complete rest. The CT group performed CT exercises, which consisted of 45 minutes of aerobic exercise. MAIN OUTCOME MEASURES: Parameters of gas exchanges: peak oxygen consumption (Vo(2)peak), first ventilator threshold (VT1), distance at six-minute walk test (6MWT), and level of anxiety and depression were measured. RESULTS: The IT group increased significantly their Vo(2)peak, the duration of the exercise test, the oxygen pulse, oxygen consumption at the VT1, and the distance walked during the 6MWT. The CT group only increased the time at the VT1 and the distance performed at the 6MWT. The improvement in the time at the VT1 was significantly higher for the IT group than for the CT group. CONCLUSIONS: This study shows that IT at very high intensity for patients with heart failure appears to be more effective than CT in improving indices of submaximal exercise capacity.

Effect of long-term physical activity practice after cardiac rehabilitation on some risk factors.

The objective of this study was to evaluate the effects of long-term physical activity practice after a cardiac rehabilitation program on weight, physical capacity and arterial compliance. The Dijon Physical Activity Score was used to identify two groups: sedentary and active. Weight, distance at the 6-min walk test and the small artery elasticity indice were measured at the beginning, at the end of the rehabilitation program and at 18.3 ± 5.3 months after. After the cardiac rehabilitation, sedentary patients showed a significant increase in weight and a significant reduction in distance on the 6-min walk test and in the arterial compliance. Active patients did not show any alteration in these parameters. We concluded that, after a cardiac rehabilitation program, the sedentary lifestyle has a negative influence on weight, physical capacity and arterial compliance, which are major markers of risk factors. In contrast, the practice of physical activity preserves these parameters.