title: [Effect of inspiratory muscle training on muscle strength and quality of life in patients with chronic airflow limitation: a randomized controlled trial].
abstract: OBJECTIVE
  Chronic airflow limitation (CAL) is a significant cause of illness and death. Inspiratory muscle training has been described as a technique for managing CAL. The aim of the present study was to evaluate the effectiveness of inspiratory muscle training on improving physiological and functional variables.
  
  
  METHODS
  Randomized controlled trial in which 35 patients with CAL were assigned to receive either an experimental (n=17) or control (n=18) intervention. The experimental intervention consisted of 2 months of inspiratory muscle training using a device that administered a resistive load of 40% of maximal static inspiratory mouth pressure (PImax). Inspiratory muscle strength, exercise tolerance, respiratory function, and quality of life were assessed.
  
  
  RESULTS
  Significant improvement in inspiratory muscle strength was observed in the experimental training group (P=.02). All patients improved over time in both groups (P<.001). PImax increased by 8.9 cm H2O per month of training. Likewise, the health-related quality of life scores improved by 0.56 points.
  
  
  CONCLUSIONS
  Use of a threshold loading device is effective for strengthening inspiratory muscles as measured by PImax after the first month of training in patients with CAL. The long-term effectiveness of such training and its impact on quality of life should be studied in a larger number of patients.
authors.affiliation: Departamento de Cirugía y Traumatología, Capacitación, Investigación y Gestión para la Salud Basada en Evidencias (CIGES), Facultad de Medicina, Universidad de la Frontera, Temuco, Chile. pseron@ufro.cl
authors.forename: P
authors.initials: P
authors.lastname: Serón
authors.forename: P
authors.initials: P
authors.lastname: Riedemann
authors.forename: S
authors.initials: S
authors.lastname: Muñoz
authors.forename: A
authors.initials: A
authors.lastname: Doussoulin
authors.forename: P
authors.initials: P
authors.lastname: Villarroel
authors.forename: X
authors.initials: X
authors.lastname: Cea
mesh_terms: D001945:Breathing Exercises; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011788:Quality of Life