Purpose: The purpose of this study was to compare the effects of interval training (IT) and continuous steady-pace training (CT) in patients with COPD.
Methods: Patients (n = 21) (mean forced expiratory volume in 1 second ([FEV1] = 44.6% +/- 13.9%) were randomized to IT, and 20 patients (mean FEV1 = 41.7% +/- 12.6%) to CT. Outcome measures included 6-minute walk distance, maximal work capacity, endurance exercise time during constant workload exercise at 60% to 70% of maximal work capacity, and quality of life including fatigue and dyspnea. Participants exercised 3 times per week for 8 weeks, and total work was the same for both training regimens.
Results: Significant improvement in mean score was observed in each variable within each of the 2 groups: 6-minute walk distance (IT = 158 +/- 178 ft, CT = 106 +/- 165 ft); maximal work capacity (IT = 10.0 +/- 13.0 W, CT = 11.5 +/- 13.1 W); endurance exercise time (IT = 15.0 +/- 12.5 minutes, CT = 18.7 +/- 10.6 minutes); and quality of life domains, fatigue (IT = 3.1 +/- 3.0, CT = 2.8 +/- 4.7), and dyspnea (IT = 4.4 +/- 5.3, CT = 5.4 +/- 5.1). There was no significant difference in the extent of improvement between the 2 training regimens for any of the outcome variables.
Conclusion: Compared with CT, IT was well tolerated and produced similar improvements in exercise performance and quality of life.