title: Changes in fatigability following intense aerobic exercise training in patients with interstitial lung disease.
abstract: OBJECTIVE
  To determine if, in patients with interstitial lung disease (ILD), fatigue might be lessened after vigorous aerobic exercise.
  
  
  METHODS
  13 physically inactive patients (5 men and 8 women; age 57.2 ± 9.1 years, BMI 28.2 ± 4.6 kgm(-2)) with ILD of heterogeneous etiology and able to walk on a motor driven treadmill without physical limitation were enrolled. Subjects underwent cardiopulmonary exercise (CPET) and 6-min walk (6MWT) tests and completed Fatigue Severity Scale and Human Activity Profile questionnaires before and after an aerobic exercise-training regimen. The training regimen required participation in at least 24 of 30 prescribed aerobic exercise training sessions at a target heart rate of 70-80% of the heart rate reserve, 30 min per session, 3 times per week for 10 weeks.
  
  
  RESULTS
  After training, a 55% (p < 0.001) increase in time to anaerobic threshold on the CPET, and an 11% (p = 0.045) reduction in performance fatigability index (PFI), calculated from the performance on the 6MWT were observed. Distance walked on the 6MWT (6MWD) increased by 49.7 ± 46.9 m (p = 0.002). Significant improvements in scores on the Fatigue Severity Scale (p = 0.046) and Human Activity Profile (AAS p = 0.024; MAS p = 0.029) were also observed. No adverse events related to the training regimen were noted.
  
  
  CONCLUSIONS
  After training, the decrease in fatigability appeared to result in increased 6MWD and was associated with physical activity. Since significant declines in 6MWD may be a marker for impending mortality in ILD, a better understanding of the etiological state of fatigue in patients with ILD and its reversal might provide fundamental insight into disease progression and even survival. [ClinicalTrials.gov identifier NCT00678821].
authors.affiliation: Department of Rehabilitation Science, College of Health and Human Services, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA; Rehabilitation Medicine Department, National Institutes of Health Clinical Center, 10 Center Drive, Bethesda, MD 20892, USA. Electronic address: rkeyser@gmu.edu.
authors.forename: Randall E
authors.initials: RE
authors.lastname: Keyser
authors.affiliation: Rehabilitation Medicine Department, National Institutes of Health Clinical Center, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Christensen
authors.affiliation: Department of Rehabilitation Science, College of Health and Human Services, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA; Rehabilitation Medicine Department, National Institutes of Health Clinical Center, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Lisa M K
authors.initials: LM
authors.lastname: Chin
authors.affiliation: Department of Rehabilitation Science, College of Health and Human Services, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA; Rehabilitation Medicine Department, National Institutes of Health Clinical Center, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Joshua G
authors.initials: JG
authors.lastname: Woolstenhulme
authors.affiliation: Rehabilitation Medicine Department, National Institutes of Health Clinical Center, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Bart
authors.initials: B
authors.lastname: Drinkard
authors.affiliation: Rehabilitation Medicine Department, National Institutes of Health Clinical Center, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Quinn
authors.affiliation: Pulmonary Rehabilitation Center, Inova Farifax Hospital, Falls Church, VA 22046, USA.
authors.forename: Gerilynn
authors.initials: G
authors.lastname: Connors
authors.affiliation: Advanced Lung Disease and Transplant Program, Inova Fairfax Hospital, 3300 Gallows Road, Falls Church, VA 22046, USA.
authors.forename: Nargues A
authors.initials: NA
authors.lastname: Weir
authors.affiliation: Advanced Lung Disease and Transplant Program, Inova Fairfax Hospital, 3300 Gallows Road, Falls Church, VA 22046, USA.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Nathan
authors.affiliation: Rehabilitation Medicine Department, National Institutes of Health Clinical Center, 10 Center Drive, Bethesda, MD 20892, USA.
authors.forename: Leighton E
authors.initials: LE
authors.lastname: Chan
mesh_terms: D000368:Aged; D015444:Exercise / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D005221:Fatigue / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D063868:Patient Outcome Assessment; D064797:Physical Conditioning, Human; D010807:Physical Endurance; D005082:Physical Exertion; D010809:Physical Fitness; D011795:Surveys and Questionnaires
keywords: Aerobic exercise physical activity; Fatigability; Fatigue severity; Interstitial lung disease; Pulmonary rehabilitation