CARDIORESPIRATORY LOAD OF EXERCISE TRAINING IN PATIENTS WITH SEVERE COPD

The effect of physical training depends on the intensity at which exer cise is performed. Patients with chronic obstructive pulmonary disease (COPD) may not tolerate high exercise intensities during training due to breathlessness. The purpose of the present study was to investigat e the cardiorespiratory load of exercise training, during pulmonary re habilitation, in patients with severe COPD. We also studied the effect s of pulmonary rehabilitation on maximum exercise performance. Thirtee n patients with stable COPD (FEV1 (S.D.) 1.0 (0.3) L) performed an inc remental cycle exercise test at baseline and after a 10 week in-patien t pulmonary rehabilitation programme. Exercise training consisted of d ynamic and isometric strength training exercises, and training of spec ific daily life activities. Training sessions were held 5 days per wee k for 10 weeks. Heart rate (HR) and dyspnoea ratings (Borg scale) were measured during one session in the second or third week of training, and were compared with values obtained during incremental cycle exerci se at baseline. The ventilatory load during the training was estimated by using the relationship between HR and minute ventilation ((V) over dotE) during incremental cycle exercise at baseline. The duration of a training session was 80 (7) min, including periods of rest. The HR d uring various exercises of the training programme varied between 94 (1 7) and 103 (14)% of peak HR during incremental cycle exercise. Borg sc ores during the training varied between 2.0 and 5.7, and were lower th an the Borg score at peak exercise (6.5 (2.0)). HR was more than 90% o f peak HR during 36 (33) min of the whole training session, which corr esponded with a (V) over dotE of 81 (11)% of peak (V) over dotE during incremental cycle exercise. Training significantly increased maximum work load (W-max) from 62 (25) to 73 (21) W (P < 0.05), without any ch ange in peak HR, (V) over dotE and (V) over dotO(2). In patients with severe COPD, the training intensity in terms of cardio-respiratory loa d was high in relation to individual maximum values. Pulmonary rehabil itation, including exercise training, improved maximum exercise perfor mance.