Interval training versus continuous training in patients with chronic obstructive pulmonary disease

■ 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.