title: Interval versus continuous training in lung transplant candidates: a randomized trial.
abstract: BACKGROUND
  Interval (IT) and continuous training (CT) represent well-established exercise modalities in patients with moderate to severe chronic obstructive pulmonary disease (COPD). However, their effects and feasibility in patients with end-stage COPD remain unclear.
  
  
  METHODS
  Sixty patients (53 ± 6 years, 53% women) being evaluated for lung transplantation where randomly assigned either to IT (n = 30, cycling at 100% peak work rate for 30 seconds alternating with 30 seconds of rest) or CT (n = 30, cycling at 60% of peak work rate) during a 3-week inpatient rehabilitation program. Both exercise protocols yielded an equivalent amount of total work. Patients had a mean forced expiratory volume at 1 second (FEV(1)) of 25% ± 8% of predicted value.
  
  
  RESULTS
  Patients in both groups achieved similar clinically relevant improvements in 6-minute walking distance of 35 ± 29 meters for IT and 36 ± 43 meters for CT, with a between-group difference of 0.3 meters (95% confidence interval, -18.2 to 18.8). Changes in lung function parameters were not significant. Perceived intensity of dyspnea was significantly (p < 0.05) lower in IT (Borg 6.2 ± 1.8) compared with CT (Borg 7.1 ± 1.7). Patients required a median of 5 unintended breaks (interquartile range, 2-28) during IT exercise and 29 (interquartile range, 6-68) during CT (p < 0.001).
  
  
  CONCLUSIONS
  IT is associated with a lower intensity of dyspnea during exercise and fewer unintended breaks but achieves similar improvements in exercise capacity compared with CT in pre-lung transplant COPD patients.
authors.affiliation: Department of Respiratory Medicine & Sports Therapy, Schoen Klinik Berchtesgadener Land, Schoenau am Koenigssee, Germany. rainer.gloeckl@gmx.de
authors.forename: Rainer
authors.initials: R
authors.lastname: Gloeckl
authors.forename: Martin
authors.initials: M
authors.lastname: Halle
authors.forename: Klaus
authors.initials: K
authors.lastname: Kenn
mesh_terms: D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000534:rehabilitation* / Q000601:surgery*; D016037:Single-Blind Method