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

Background: Beneficial training outcomes have been reported in sedentary pa tients with chronic heart failure (CHF) after exercise training. However, d ata on training effects in previously trained patients, as well as comparis ons of different exercise modes, are lacking. The aim of this study is to c ompare exercise training on a cycle ergometer (major muscle mass) and aerob ic knee-extensor training (minor muscle mass) in previously trained patient s 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 st ratification for sex, age, ejection fraction, and cardiac output response, the training group was further randomized to either cycle ergometer or knee -extensor training fur 8 weeks. The control and training patients did not d iffer at baseline, and the measured variables did not change in the control group during the 8 weeks. Citrate synthase activity in skeletal muscle inc reased after cycle training (23%; P < .02) and knee-extensor training (45%; P < .008), and blood lactate concentration at submaximal intensities decre ased (P < .01) in both groups. However. only after knee-extensor training d id the peak oxygen uptake increase (19%; P < .01) and sympathetic nervous s ystem activity, measured as plasma norepinephrine concentration at rest (P < .05) and during exercise (P < .008), decrease. Minnesota Living with Hear t Failure questionnaire scores also showed improvement in the health-relate d quality of life (P < .05) only after knee-extensor training. Conclusion: Physical training is beneficial in previously trained patients with CHF, Ae robic training involving a minor muscle mass shows greater efficiency than training involving a. major muscle mass.