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Background: In patients with CHF, physical reconditioning improves exercise tolerance and endurance capacity. However, there is no evidence that endurance training programs affect skeletal muscle strength in such patients.Design: The present study investigates the effects of endurance training on isokinetic skeletal muscle strength and on aerobic capacity in chronic heart failure (CHF) patients.Methods: Eleven stable CHF patients (8 men, mean aged 54.3 yr and women, mean aged 49.3 yr) participated in a classical controlled inhospital 8-week endurance training program. Progressive incremental exercise tests with gas exchange analysis and isokinetic strength measurements of knee flexors and extensors were conducted in all subjects before and after training at different angular velocities (60, 180, 240 degrees/s ).Results: After training, peak &Vdot; O_2 improved significantly (from 16.3 +/- 3.3 to 20.7 +/- 4.0 ml/kg/min; p < 0.002) as did New York Heart Association (NYHA) functional class (2.2 +/- 0.4 to 1.5 +/- 0.5; p < 0.001). Conversely, isokinetic strength at all angular velocities studied was unchanged after the training program.Conclusion: Isokinetic muscle strength was not improved in CHF patients participating in a endurance training program. A combined endurance and resistance protocol might be helpful for these patients whose frequently altered muscle strength undoubtedly contributes to their poor quality of life for everyday activities. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the relationship between isokinetic strength, and aerobic aptitude in patients with chronic heart failure (CHF) and with chronic obstructive pulmonary disease (COPD). Methods: Seventeen stable CHF (n=11) and COPD (n=6) patients aged 51.12 +/- 9.95 ys old (15 men, 2 women, CHF patients: NYHA class II: n=8 and III: n=3) underwent a dynamic isokinetic force evaluation of the quadriceps (IsoK) at an angular velocity of 180 degrees/s [-1], a symptom-limited cardiopulmonary exercise test with simultaneous monitoring of respiratory gases, and a 6-min walking test. Body composition was assessed by electrical bioimpedance. The relationships between muscle strength, maximal aerobic performance, results of endurance tests and anthropometric datas were assessed by simple regression analysis. Results: The isokinetic evaluation has been successfully performed in all patients. No cardiac arrhythmic event nor abnormal haemodynamic response was observed in either group of patients. In CHF patients, individual quadricipital muscle strength was significantly related to fat-free mass (r=0.862; p<0.01). However, neither peak O[2] (global: r=0.562, p=NS or weight-adjusted: r=0.083, p=NS) nor endurance capacity (r=0.068, p=NS) were significantly related to the peripheral muscle strength. In COPD patients, quadricipital muscle strength was not significantly related to fat-free mass (r=0.242; p=NS) nor any other measured factor. Conclusion: Physiopathological mechanisms of exercise limitation in CHF and COPD patients are complex. Isokinetic strength and O_2 peak are not related to each other and are therefore independent. Therefore, a systematic evaluation of isokinetic muscle strength may be of great value. Early degradations in aerobic capacity are probably followed by an alteration in muscle strength. [ABSTRACT FROM AUTHOR]