Effectiveness of Interval Exercise Training in Patients with COPD

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.

Keywords: chronic obstructive pulmonary disease; exercise tolerance; interval exercise training; pulmonary rehabilitation.

Figure 1

Time course of a) dyspnea, b) leg fatigue assessed with the 0-10 Borg Scale and c) blood lactate concentration during interval (open circles) and constant-load (closed circles) exercise. *asterisks denotes significant differences (p < .05) between exercise modes. Modified from the European Respiratory Society.

Figure 2

Total exercise time (min) and total work rate (% WRmax) with continuous exercise training in studies with COPD patients of different disease severity. Each symbol represents a different exercise training intensity in patients with FEV₁ > 40% predicted (refs:8,23,51,56,59) and FEV₁ < 40% predicted (refs: 26,55,57,58).

Figure 3

Oxygen uptake (VO₂) and minute ventilation (VE) in COPD patients during interval (open circles) and constant-load (closed circles) exercise protocol. Interval exercise was sustained for 30 sec at 100% of peak baseline capacity alternated by 30 sec rest, whereas continuous exercise was sustained at 75% of peak baseline capacity. Modified from the European Respiratory Society.