title: Pulmonary Rehabilitation in COPD: Effect of 2 Aerobic Exercise Intensities on Subject-Centered Outcomes--A Randomized Controlled Trial.
abstract: BACKGROUND
  Exercise training is an important component of pulmonary rehabilitation, but it remains questionable how training intensity affects patient-centered outcomes. The aim of this study was to compare the effects of 2 aerobic training intensities on health-related quality of life (HRQOL), symptom control, and exercise tolerance in subjects with COPD.
  
  
  METHODS
  Thirty-four subjects with mild to very severe COPD participated in an equivalence/non-inferiority randomized controlled trial with a parallel group blinded to 60 or 80% maximum work rate (W max) aerobic training intensity. The intervention was an out-patient pulmonary rehabilitation program conducted 3 times/week for 8 weeks. Outcomes were assessed with the St George Respiratory Questionnaire (primary outcome), Mahler's dyspnea index, London Chest Activity of Daily Living scale, 6-min walk test, and constant-load and incremental exercise tests.
  
  
  RESULTS
  Subjects were randomly allocated to aerobic training intensity of 60% W max (group 1, n = 17) or 80% W max (group 2, n = 17). Although there were significant improvements in all outcomes for both groups, there were no between-group differences in mean change in the St George Respiratory Questionnaire (P = .31, 95% CI -12.0 to 3.9), Mahler's dyspnea index (P = .38), London Chest Activity of Daily Living scale (P = .92), 6-min walk test (P = .50, 95% CI 6.2-71.1), constant-load exercise test (P = .50), and incremental exercise test (P = .12). There was only one exercise-related adverse event of cardiac symptoms.
  
  
  CONCLUSIONS
  Aerobic training intensity of at least 60% W max has a positive impact on COPD patient-centered outcomes, with no additional benefit of increasing intensity to 80% W max in HRQOL, symptom control, and exercise tolerance, challenging the present clinical attitude of rehabilitation professionals. (ClinicalTrials.gov registration NCT01944072.).
authors.affiliation: Fisioterapia, Centro Hospitalar de Lisboa Ocidental-Hospital de Egas Moniz, Lisbon, Portugal. fisiocsantos@gmail.com.
authors.forename: Catarina
authors.initials: C
authors.lastname: Santos
authors.affiliation: Serviço de Pneumologia, Centro Hospitalar Lisboa Norte (CHLN)-Hospital Pulido Valente, and NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.
authors.forename: Fátima
authors.initials: F
authors.lastname: Rodrigues
authors.affiliation: Unidade de Reabilitação Respiratória, Serviço de Pneumologia, CHLNHospital Pulido Valente, Lisbon, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Santos
authors.affiliation: Unidade de Reabilitação Respiratória, Serviço de Pneumologia, CHLNHospital Pulido Valente, Lisbon, Portugal.
authors.forename: Luísa
authors.initials: L
authors.lastname: Morais
authors.affiliation: Serviço de Pneumologia, CHLN-Hospital Pulido Valente, and the Faculdade de Medicina da Universidade de Lisboa, Instituto de Saúde Ambiental (ISAMB), Lisbon, Portugal.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bárbara
mesh_terms: D000368:Aged; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D008297:Male; D055686:Metabolic Equivalent; D008875:Middle Aged; D063868:Patient Outcome Assessment; D005082:Physical Exertion / Q000502:physiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000534:rehabilitation*; D011788:Quality of Life; D055070:Resistance Training; D016037:Single-Blind Method; D063189:Symptom Assessment
keywords: COPD; aerobic training; exercise intensity; health-related quality of life; rehabilitation