title: Effects of light-emitting diodes on muscle fatigue and exercise tolerance in patients with COPD: study protocol for a randomized controlled trial.
abstract: BACKGROUND
  Light-emitting diodes (LED) have been used to minimize muscle fatigue in athletes and healthy subjects. Patients with chronic obstructive pulmonary disease (COPD) are susceptible to early muscle fatigue.
  
  
  OBJECTIVE
  The objective of this study is to investigate the acute effects of LED on muscle function, exercise capacity and cardiorespiratory responses during isometric and dynamic exercise in patients with COPD.
  
  
  METHODS
  This study will assess 30 patients with moderate to severe obstruction (forced expiratory volume-one second,FEV1 ≤70% predicted). Isometric and dynamic protocols will be conducted in two visits each, for a total of four visits a week apart. First, venous blood will be taken from the patients. The isometric protocol will start with the determination of the maximum voluntary isometric contraction (MIVC) to determine the workload (60% of MIVC) for the isometric endurance test (IET). Patients will be randomized to receive either the placebo or LED application (each point will be irradiated for 30 s and the energy received at each point will be 41.7 J). Immediately after finishing this procedure, the patients will carry out the IET until the limit of tolerance or until a 20% fall of strength is observed. After the test, another blood draw will be taken. In another visit (one week later), the same order of procedures will be performed, except with the opposite (LED or placebo). For the dynamic endurance test (DET), the same procedures described above will be followed, except with 75% of the maximal workload obtained from the incremental cycle ergometer test used instead of the IET. The electromyography will be recorded during the isometric and dynamic protocols. Differences in muscle function, exercise capacity and cardiorespiratory responses between the LED and placebo applications will be analyzed. The therapeutic effects of LED could minimize muscle fatigue in patients with COPD by increasing exercise tolerance.
  
  
  BACKGROUND
  
  
  
  BACKGROUND
  NCT01448564.
authors.affiliation: Post Graduate Program in Rehabilitation Sciences, Nove de Julho University, São Paulo, Brazil.
authors.forename: Eduardo Foschini
authors.initials: EF
authors.lastname: Miranda
authors.forename: Ernesto Cesar Pinto
authors.initials: EC
authors.lastname: Leal-Junior
authors.forename: Paulo Henrique
authors.initials: PH
authors.lastname: Marchetti
authors.forename: Simone
authors.initials: S
authors.lastname: Dal Corso
mesh_terms: D015415:Biomarkers / Q000097:blood; D001938:Brazil; D002985:Clinical Protocols; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004576:Electromyography; D005080:Exercise Test; D017079:Exercise Tolerance; D005541:Forced Expiratory Volume; D006801:Humans; D007537:Isometric Contraction; D008168:Lung / Q000503:physiopathology; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology*; D010789:Phototherapy / Q000295:instrumentation*; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D012107:Research Design; D012720:Severity of Illness Index; D013147:Spirometry; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers