Interval versus continuous training in patients with severe COPD: a randomized clinical trial. R. Coppoolse, A.M.W.J. Schols, E.M. Baarends, R. Mostert, M.A. Akkermans, P.P. Janssen, E.F.M. Wouters. #ERS Journals Ltd 1999. ABSTRACT: Limited information is available regarding the physiological responses to different types of exercise training in patients with severe chronic obstructive pulmonary disease (COPD). The aim of this study was two fold: firstly, to investigate the physiological response to training at 60% of achieved peak load in patients with severe COPD; and secondly to study the effects of interval (I) versus continuous (C) training in these patients.Twenty-one patients with COPD (mean SD forced expiratory volume in one second: 37 15% of predicted, normoxaemic at rest) were evaluated at baseline and after 8 weeks' training. Patients were randomly allocated to either I or C training. The training was performed on a cycle ergometer, 5 days a week, 30 min daily. The total work load was the same for both training programmes.C training resulted in a significant increase in oxygen consumption (V 'O 2 ) (17%, p<0.05) and a decrease in minute ventilation (V 'E)/V 'O 2 (p<0.01) and V 'E/carbon dioxide production (V 'CO 2 ) (p<0.05) at peak exercise capacity, while no changes in these measures were observed after interval training. During submaximal exercise a significant decrease was observed in lactic acid production, being most pronounced in the C-trained group (-31%, p<0.01 versus -20%, p<0.05). Only in the I-trained group did a significant increase in peak work load (17%, p<0.05) and a decrease in leg pain (p<0.05) occur. Training did not result in a significant improvement in lung function, but maximal inspiratory mouth pressure increased in both groups by 10% (C: p<0.05) and 23% (I: p<0.01).The present study shows a different physiological response pattern to interval or continuous training in chronic obstruction pulmonary disease, which might be a reflection of specific training effects in either oxidative or glycolytic muscle metabolic pathways. Further work is required to determine the role of the different exercise programmes and the particular category of patients for whom this might be beneficial. Eur Respir J 1999; 14: 258±263. Pulmonary rehabilitation has become a cornerstone in an integrated management of patients with chronic obstructive pulmonary disease (COPD) [1]. Dyspnoea and an impaired exercise tolerance are prominent complaints in these patients and exercise training is therefore an essential component of a pulmonary rehabilitation programme [1]. Although several studies have shown beneficial effects of exercise training on exercise tolerance in COPD, the question persists as to whether these increases are principally due to improved psychological benefits of pulmonary rehabilitation or to improved physiological ability to perform exercise.The physiological response to exercise depends on four training principles [2]. 1) A specific exercise overload must be applied to enhance physiologi...

Clear evidence for an association between systemic inflammation and increased arterial stiffness in patients with chronic obstructive pulmonary disease (COPD) is lacking. Moreover, the effects of pulmonary rehabilitation on arterial stiffness are not well studied.We aimed to 1) confirm increased arterial stiffness in COPD; 2) evaluate its correlates including systemic inflammation; and 3) study whether or not it is influenced by pulmonary rehabilitation.Aortic pulse-wave velocity (APWV) was determined in 168 healthy volunteers, and APWV and inflammatory markers were determined in 162 COPD patients during baseline evaluation of a pulmonary rehabilitation programme. A complete post-pulmonary rehabilitation dataset was collected in 129 patients.It was found that APWV was increased in COPD patients when compared with controls, blood pressure and age predicted baseline APWV, and systemic inflammatory markers were not independently related to APWV. Although baseline APWV was predictive for the change in APWV after pulmonary rehabilitation (r5 -0.77), on average APWV did not change (10.7¡2.7 versus 10.9¡2.5 m?s -1 ; p50.339). Arterial stiffness in COPD is not related to systemic inflammation and does not respond to state-of-theart pulmonary rehabilitation. These results emphasise the complexity of cardiovascular risk and its management in COPD. @ERSpublications Arterial stiffness in COPD is not related to systemic inflammation and does not respond to pulmonary rehabilitation

The effect of exercise at different intensities as well as the effect of intensive supervised pulmonary rehabilitation on oxidative stress were studied for chronic obstructive pulmonary disease (COPD). Eleven patients with COPD and 11 healthy age-matched control subjects performed a maximal and submaximal exercise cycle ergometry test at 60% of peak workload. Patients with COPD performed these tests before and after 8 wk of pulmonary rehabilitation. Measurements were done before, immediately after, and 4 h after both exercise tests. At rest, increased oxidative stress was observed in patients compared with control subjects, as measured by urinary malondialdehyde (MDA; p < 0.05) and hydrogen peroxide (H2O2) in breath condensate (p < 0.05). In healthy control subjects, a significant increase in urinary MDA was observed 4 h after both exercise tests (p = 0.05), whereas H2O2 significantly increased immediately after maximal exercise (p < 0.05). In patients with COPD, before rehabilitation, reactive oxygen species-induced DNA damage in peripheral blood mononuclear cells, urinary MDA, and plasma uric acid were significantly increased after both exercise tests (p < 0.05), whereas no significant increase was observed in plasma MDA. In contrast, exhaled H2O2 was only significantly increased after maximal exercise (p < 0.02). Although after rehabilitation peak workload was increased by 24%, a similar oxidative stress response was found. Remarkably, a decrease in reactive oxygen species-induced DNA damage was detected after exercise at submaximal intensity despite increased exercise duration of 73%. In summary, patients with COPD had increased pulmonary and systemic oxidative stress both at rest and induced by exercise. In addition, pulmonary rehabilitation increased exercise capacity and was associated with reduced exercise-induced oxidative stress.

Exercise intolerance is common in hemodialysis (HD) and renal transplant (RTx) patients. Aim of the study was to assess to what extent exercise capacity and skeletal muscle strength of RTx patients differ from HD patients and healthy controls and to elucidate potential determinants of exercise capacity in RTx patients. Exercise capacity, muscle strength, lean body mass (LBM) and physical activity level (PAL) were measured by cycle-ergometry, isokinetic dynamometry, DEXA and Baecke Questionnaire, respectively, in 35 RTx, 16 HD and 21 controls. VO 2 peak and muscle strength of the RTx patients were significantly lower compared to controls (p < 0.01), but not different compared to HD patients. In RTx patients, strength (p < 0.001), PAL (p = 0.001) and age (p = 0.045) were significant predictors of VO 2 peak. Muscle strength was related to LBM (p = 0.001) and age (p = 0.001), whereas gender (p < 0.001) and renal function (p = 0.01) turned out to be significant predictors of LBM. No effects of corticosteroids were observed. Exercise capacity and muscle strength seem equally reduced in RTx and HD patients compared to controls. In RTx patients, muscle strength and PAL are highly related to exercise capacity. Renal function appears to be a significant predictor of LBM, and through the LBM, of muscle strength and exercise capacity.

Resistance training and transcutaneous neuromuscular electrical stimulation (NMES) are new modalities in rehabilitation of severely disabled patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to compare the metabolic response during resistance training and during NMES of the quadriceps femoris muscles in patients with COPD entering pulmonary rehabilitation. Pulmonary function, body composition, peak aerobic capacity, the Medical Research Council dyspnoea grade, the one-repetition maximum strength assessment were evaluated in 13 COPD patients. Additionally, peak oxygen uptake, peak minute ventilation and Borg symptom scores were assessed during a resistance training session and a NMES session. The median peak oxygen uptake and median peak minute ventilation during the resistance training session were significantly higher compared to the NMES session. Additionally, these higher metabolic responses were accompanied by higher symptom Borg scores for dyspnoea and leg fatigue. To conclude, the metabolic response was significantly lower during a NMES session compared to a resistance exercise training session in patients with COPD. Nevertheless, both modalities seem to result in an acceptable metabolic response accompanied by a clinically acceptable sensation of dyspnoea and leg fatigue.