Aerobic training involving a minor muscle mass shows greater efficiency than training involving a major muscle mass in chronic heart failure patients

Abstract

Background: Beneficial training outcomes have been reported in sedentary patients with chronic heart failure (CHF) after exercise training. However, data on training effects in previously trained patients, as well as comparisons of different exercise modes, are lacking. The aim of this study is to compare exercise training on a cycle ergometer (major muscle mass) and aerobic knee-extensor training (minor muscle mass) in previously trained patients with CHF. Methods and Results: Twenty-four men and women (age, 63 ± 10 years [mean ± SD]) with stable, moderate CHF (left ventricular ejection fraction, 30% ± 11%) who had completed their first exercise training period more than 1 year ago were allocated to either the exercise or control group. After stratification for sex, age, ejection fraction, and cardiac output response, the training group was further randomized to either cycle ergometer or knee-extensor training for 8 weeks. The control and training patients did not differ at baseline, and the measured variables did not change in the control group during the 8 weeks. Citrate synthase activity in skeletal muscle increased after cycle training (23%; P < .02) and knee-extensor training (45%; P < .008), and blood lactate concentration at submaximal intensities decreased ( P < .04) in both groups. However, only after knee-extensor training did the peak oxygen uptake increase (19%; P < .01) and sympathetic nervous system activity, measured as plasma norepinephrine concentration at rest ( P < .05) and during exercise ( P < .008), decrease. Minnesota Living with Heart Failure questionnaire scores also showed improvement in the health-related quality of life ( P < .05) only after knee-extensor training. Conclusion: Physical training is beneficial in previously trained patients with CHF. Aerobic training involving a minor muscle mass shows greater efficiency than training involving a major muscle mass.