Supervised high intensity continuous and interval training vs. self-paced training in COPD.

Background: Endurance training is an effective component of pulmonary rehabilitation in COPD. Controversy exists regarding whether different modalities of supervised exercise training (continuous (C) or interval (I)) or self-paced (S) programs are equally beneficial.

Methods: Seventy-one patients with COPD (average FEV(1)=55% predicted) were assigned to 8 weeks of C, I or S training, 45 min/session, 3 times/week. Group C (n=22) exercised at 80% of pre-training peak work rate in an incremental cycle ergometer test. In group I (n=17), training consisted of 30 min of cycling 2 min at 90% followed by 1 min at 50% peak work rate bracketed by 7.5 min at 50% peak work rate. The S group (n=32) was instructed to cycle, climb stairs and walk in their home with the same periodicity and time intervals.

Results: Improvement in incremental test peak work rate was significant in both C and I groups, but not in S. Peak oxygen uptake and lactic acidosis threshold improved significantly in the supervised groups, but differences among groups did not achieve significance. Scores in an activity questionnaire improved in all groups without significant differences among groups.

Conclusions: In COPD patients, continuous and interval training have similar physiologic effects; by some measures of endurance exercise performance, they are superior to self-paced training. However, all were effective in improving patient-perceived activity.