title: Development and implementation of treadmill exercise testing protocols in COPD.
abstract: BACKGROUND
  Because treadmill exercise testing is more representative of daily activity than cycle testing, we developed treadmill protocols to be used in various clinical settings as part of a two-year, multicenter, chronic obstructive pulmonary disease (COPD) trial evaluating the effect of tiotropium on exercise.
  
  
  METHODS
  We enrolled 519 COPD patients aged 64.6 ± 8.3 years with a postbronchodilator forced expiratory volume in one second (FEV(1)) of 1.25 ± 0.42 L, 44.3% ± 11.9% predicted. The patients performed symptom-limited treadmill tests where work rate (Ẇ) was increased linearly using speed and grade adjustments every minute. On two subsequent visits, they performed constant Ẇ tests to exhaustion at 90% of maximum Ẇ from the incremental test.
  
  
  RESULTS
  Mean incremental test duration was 522 ± 172 seconds (range 20-890), maximum work rate 66 ± 34 watts. For the first and second constant Ẇ tests, both at 61 ± 33 watts, mean endurance times were 317 ± 61 seconds and 341 ± 184 seconds, respectively. The mean of two tests had an intraclass correlation coefficient of 0.85 (P < 0.001). During the second constant Ẇ test, 88.2% of subjects stopped exercise because of breathing discomfort; 87.1% for Global Initiative for Chronic Obstructive Lung Disease (GOLD) Stage II, 88.5% for GOLD Stage III, and 90.2% for GOLD Stage IV.
  
  
  CONCLUSIONS
  The symptom-limited incremental and constant work treadmill protocol was well tolerated and appeared to be representative of the physiologic limitations of COPD.
authors.affiliation: David Geffen School of Medicine, University of California, Los Angeles, CA 90095-1690, USA. ccooper@mednet.ucla.edu
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Cooper
authors.forename: Marlon
authors.initials: M
authors.lastname: Abrazado
authors.forename: Daniel
authors.initials: D
authors.lastname: Legg
authors.forename: Steven
authors.initials: S
authors.lastname: Kesten
mesh_terms: D000368:Aged; D001993:Bronchodilator Agents / Q000627:therapeutic use; D018680:Cholinergic Antagonists / Q000627:therapeutic use; D005080:Exercise Test; D017079:Exercise Tolerance; D005240:Feasibility Studies; D005260:Female; D005541:Forced Expiratory Volume; D005858:Germany; D006801:Humans; D015141:Los Angeles; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D012602:Scopolamine Derivatives / Q000627:therapeutic use; D012720:Severity of Illness Index; D013997:Time Factors; D000069447:Tiotropium Bromide; D016896:Treatment Outcome; D014797:Vital Capacity
chemical_list: D001993:Bronchodilator Agents; D018680:Cholinergic Antagonists; D012602:Scopolamine Derivatives; D000069447:Tiotropium Bromide