Background: Passive training of specific locomotor muscle groups by means of neuromuscular electrical stimulation (NMES) might be better tolerated than whole body exercise in patients with severe chronic obstructive pulmonary disease (COPD). It was hypothesised that this novel strategy would be particularly effective in improving functional impairment and the consequent disability which characterises patients with end stage COPD. Methods: Fifteen patients with advanced COPD (nine men) were randomly assigned to either a home based 6 week quadriceps femoris NMES training programme (group 1, n=9, FEV 1 =38.0 (9.6)% of predicted) or a 6 week control period before receiving NMES (group 2, n=6, FEV 1 =39.5 (13.3)% of predicted). Knee extensor strength and endurance, whole body exercise capacity, and health related quality of life (Chronic Respiratory Disease Questionnaire, CRDQ) were assessed. Results: All patients were able to complete the NMES training programme successfully, even in the presence of exacerbations (n=4). Training was associated with significant improvements in muscle function, maximal and endurance exercise tolerance, and the dyspnoea domain of the CRDQ (p<0.05). Improvements in muscle performance and exercise capacity after NMES correlated well with a reduction in perception of leg effort corrected for exercise intensity (p<0.01). Conclusions: For severely disabled COPD patients with incapacitating dyspnoea, short term electrical stimulation of selected lower limb muscles involved in ambulation can improve muscle strength and endurance, whole body exercise tolerance, and breathlessness during activities of daily living.

The clinical and physiological effects of a medically supervised, indoor physical training programme were investigated in 36 asthmatic subjects aged 16-40 years. After clinical evaluation, lung function assessment, and progressive incremental exercise testing subjects were randomly allocated to control and training groups. The measurements were repeated after a six week run in period and after a further three months in which those in the training group underwent an indoor training programme. The measurements made at three months were compared with those at the end of the run in period. There was no significant change in anthropometric characteristics, blood lipid profiles, or the provocative concentration of histamine causing a 20% fall in FEV, (histamine PC20) in the group who underwent training. After training there were significant increases in mean maximal oxygen uptake (ml kg' mini') from 23 (5) to 28 (6), oxygen pulse (ml/beat) from 8-8 (2 3) to 10-8 (2 4), and anaerobic threshold (1/min) from 1 11 (0 27) to

L Lo ow w i in nt te en ns si it ty y p pe er ri ip ph he er ra al l m mu us sc cl le e c co on nd di it ti io on ni in ng g i im mp pr ro ov ve es s e ex xe er rc ci is se e t to ol le er ra an nc ce e a an nd d b br re ea at th hl le es ss sn ne es ss s i in n C CO OP PD D ABSTRACT: This randomized, controlled study investigated the physiological effects of a specially designed 12 week programme of isolated conditioning of peripheral skeletal muscle groups. The programme required minimal infrastructure in order to allow continued rehabilitation at home after familiarization within hospital. Forty eight patients, aged 40-72 yrs with chronic obstructive pulmonary disease (COPD) (mean (SD) forced expiratory volume in one second (FEV1) 61 (27)% of predicted normal) were randomly allocated into training (n=32) and control (n=16) groups. Physiological assessments were performed before and after the 12 week study period, and included peripheral muscle endurance and strength, whole body endurance, maximal exercise capacity (maximum oxygen consumption (V ' 'O 2 ,max)) and lung function.The training group showed significant improvement in a variety of measures of upper and lower peripheral muscle performance, with no additional breathlessness. Whole body endurance measured by free arm treadmill walking increased by 6,372 (3,932-8,812) J (p<0.001). Symptom-limited maximal V ' 'O 2 was unchanged. However, the training group showed a reduction in ventilatory equivalents for oxygen and carbon dioxide, both at peak exercise and at equivalent work rate (Wmax).In summary, low intensity isolated peripheral muscle conditioning is well-tolerated, simple and easy to perform at home. The various physiological benefits should enable patients across the range of severity of chronic obstructive pulmonary disease to improve daily functioning.

This study poses two questions: 1) is there an abnormality in isokinetic skeletal muscle strength and endurance in mild chronic obstructive pulmonary disease (COPD)? and 2) what is the effect of a randomized, controlled, 12 week hospital outpatient weight training programme in terms of skeletal muscle function and exercise tolerance?Upper and lower limb isokinetic maximum and sustained muscle function were compared in 43 COPD patients (age 4911 yrs), mean forced expiratory volume in one second (FEV1) 7723% pred and 52 healthy, sedentary subjects (age 51 (10) yrs), mean FEV1 10916% pred. The 43 COPD patients were randomly 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 exception of sustained upper limb strength) as compared with healthy sedentary subjects. 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 mild chronic obstructive pulmonary disease which cannot be explained by factors such as hypoxaemia and malnutrition. Intervention with weight training is effective in countering this deficit which the authors conclude is probably due to muscle deconditioning. Eur Respir J 2000; 15: 92±97.

In view of the lack of objective information on work performance in asthma, a progressive incremental exercise test was carried out in 44 subjects with mild to moderate asthma and 64 normal, healthy subjects matched for habitual activity, to compare cardiorespiratory fitness and to determine the relative contribution of airflow obstruction to exercise limitation. The two groups achieved similar maximum heart rates (mean (SD) 176(12) and 175(10) beats/min). After allowance for confounding factors the asthmatic subjects had a lower maximum oxygen consumption (Vo2 max) (by 199 ml min-) than control subjects. Having asthma also accounted for a significant reduction in anaerobic threshold (125 ml min-') and oxygen pulse (0-805 ml/beat). There was no correlation of FEV1 with V02 max, anaerobic threshold, or oxygen pulse either before or after bronchodilator. The dyspnoea index (VE/MW%) was increased in the asthmatic subjects at peak exercise, but was less than 60% in all subjects at a workload that produced 75% ofthe predicted maximum heart rate. Thus the asthmatic subjects had a maximum heart rate similar to that of normal subjects but the low Vo2 max, anaerobic threshold, and oxygen pulse suggest suboptimal fitness, which was not directly due to airflow obstruction. All had sufficient ventilatory reserve to allow toleration of training at a work intensity adequate to permit improvements in cardiovascular fitness.

The relationship between asthma and exercise and the resultant disability (ie, the impact on activities of daily living, including physical activity) shows wide interpatient and intrapatient variability, being influenced not only by the disease but additional psychosocial variables. There are a variety of helpful pharmacologic and nonpharmacologic measures in dealing with simple exercise-induced asthma, and new therapeutic options are being developed. The cardiorespiratory performance characteristics of asthmatic patients are very frequently suboptimal, either because of symptom-limited exercise tolerance or secondary deconditioning consequent upon inactivity. Medically supervised physical training can produce significant beneficial change. Recommendations for rehabilitation of asthmatic patients would include individualized exercise prescription and advice based on objective criteria of exercise capability, with flexibility in the programs offered, in order to cater to the broadest spectrum of patient disability.