ABSTRACT
Physical training is beneficial and should be included in the comprehensive management of all patients with COPD independently of disease severity. Different rehabilitative strategies and training modalities have been proposed to optimize exercise tolerance. Interval exercise training has been used as an effective alternative modality to continuous exercise in patients with moderate and severe COPD.Although in healthy elderly individuals and patients with chronic heart failure there is evidence that this training modality is superior to continuous exercise in terms of physiological training effects, in patients with COPD, there is not such evidence. Nevertheless, in patients with COPD application of interval training has been shown to be equally effective to continuous exercise as it induces equivalent physiological training effects but with less symptoms of dyspnea and leg discomfort during training.The main purpose of this review is to summarize previous studies of the effectiveness of interval training in COPD and also to provide arguments in support of the application of interval training to overcome the respiratory and peripheral muscle limiting factors of exercise capacity. To this end we make recommendations on how best to implement interval training in the COPD population in the rehabilitation setting so as to maximize training effects.
ABSTRACT
The BODE index is frequently used to assess functional capacity in patients with COPD. The aim of this study was to investigate the effectiveness of interval-load training (ILT) to improve the BODE index in comparison to the commonly implemented constant-load training (CLT). Forty-two patients with COPD [FEV(1): (mean+/-SEM) 42+/-3% predicted] were randomly allocated to either ILT (n=21) or CLT (n=21). The training program consisted of cycling exercise 3 days/week for 10 weeks. Patients assigned to ILT exercised at a mean intensity of 126+/-4% of baseline peak work rate (Wpeak) with 30-s work periods alternated with 30-s rest periods for 45 min per day, whereas patients allocated to CLT exercised at a mean intensity of 76+/-5% of baseline Wpeak for 30 min per day. The BODE index and its components: body mass index, FEV(1), MMRC dyspnea score and the 6-min walk test (6-MWT) as well as cycling Wpeak were assessed before and after both exercise training regimes. Both ILT and CLT significantly (p<0.001) decreased the BODE index (from 4.8+/-0.5 to 4.0+/-0.5 units and from 4.4+/-0.5 to 3.8+/-0.5 units, respectively). In addition, both ILT and CLT significantly decreased the MMRC dyspnea score by 0.4+/-0.1 units and increased the 6-MWT (by 52+/-16 and 44+/-12 m, respectively) as well as cycling Wpeak (by 14+/-2 and 10+/-2W, respectively). The magnitude of these changes was not significantly different between ILT and CLT. Consequently, ILT is equally effective to CLT in terms of improving the BODE index in patients with COPD and as such it may constitute an alternative rehabilitative modality in COPD.
