title: Safety and possible effects of low-intensity resistance training associated with partial blood flow restriction in polymyositis and dermatomyositis.
abstract: BACKGROUND
  Our aim was to evaluate the safety and efficacy of a low-intensity resistance training program combined with partial blow flow restriction (BFR training) in a cohort of patients with polymyositis (PM) and dermatomyositis (DM).
  
  
  METHODS
  In total, 13 patients with PM and DM completed a 12-week twice a week low-intensity (that is, 30% one-repetition-maximum (1RM)) resistance exercise training program combined with partial blood flow restriction (BFR). Assessments of muscle strength, physical function, quadriceps cross sectional (CSA) area, health-related quality of life, and clinical and laboratory parameters were assessed at baseline and after the intervention.
  
  
  RESULTS
  The BFR training program was effective in increasing the maximal dynamic strength in both the leg-press (19.6%, P <0.001) and knee-extension exercises (25.2% P <0.001), as well as in the timed-stands (15.1%, P <0.001) and timed-up-and-go test (-4.5%, P =0.002). Quadriceps CSA was also significantly increased after the intervention (4.57%, P =0.01). Similarly, all of the components of the Short Form-36 Health Survey, the Health Assessment Questionnaire scores, and the patient- and physician reported Visual Analogue Scale were significantly improved after training (P <0.05). Importantly, no clinical evidence or any other self-reported adverse event were found. Laboratory parameters (creatine kinase and aldolase) were also unchanged (P >0.05) after the intervention.
  
  
  CONCLUSIONS
  We demonstrated that a 12-week supervised low-intensity resistance training program associated with partial blood flow restriction may be safe and effective in improving muscle strength and function as well as muscle mass and health-related quality of life in patients with PM and DM.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT01501019. Registered November 29, 2011.
authors.forename: Melina Andrade
authors.initials: MA
authors.lastname: Mattar
authors.forename: Bruno
authors.initials: B
authors.lastname: Gualano
authors.forename: Luiz Augusto
authors.initials: LA
authors.lastname: Perandini
authors.forename: Samuel Katsuyuki
authors.initials: SK
authors.lastname: Shinjo
authors.forename: Fernanda Rodrigues
authors.initials: FR
authors.lastname: Lima
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Sá-Pinto
authors.forename: Hamilton
authors.initials: H
authors.lastname: Roschel
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D003882:Dermatomyositis / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000503:physiopathology; D017285:Polymyositis / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000098:blood supply / Q000503:physiopathology; D011788:Quality of Life; D055070:Resistance Training / Q000379:methods*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D064232:Visual Analog Scale