Skeletal muscle strength and endurance in patients with mild COPD and the effects of weight training

This study poses two questions: 1) is there an abnormality in isokinetic sk eletal muscle strength and endurance in mild chronic obstructive pulmonary disease (COPD)? and 2) what is the effect of a randomized, controlled, 12 w eek hospital outpatient weight training programme in terms of skeletal musc le function and exercise tolerance? Upper and lower limb isokinetic maximum and sustained muscle function were compared in 43 COPD patients (age 49+/-11 yrs), mean forced expiratory volu me in one second (FEV1) 77+/-23% pred and 52 healthy, sedentary subjects (a ge 51 (10) yrs), mean FEV1 109+/-16% pred. The 43 COPD patients were random ly allocated into training (n=26) and control (n=17) groups. Isokinetic and isotonic muscle function, whole body endurance, maximal exercise capacity and lung function were measured. The COPD patients had reduced isokinetic muscle function (with the exceptio n of sustained upper limb strength) as compared,vith healthy sedentary subj ects. Muscle function improved after weight training in the COPD patients. Whole body endurance during treadmill walking also improved with no change in maximal oxygen consumption. A deficit in skeletal muscle function can be identified in patients with mi ld chronic obstructive pulmonary disease which cannot be explained by facto rs such as hypoxaemia and malnutrition. Intervention with weight training i s effective in countering this deficit which the authors conclude is probab ly due to muscle deconditioning.