title: Effects of short versus long bouts of aerobic exercise in sedentary women with fibromyalgia: a randomized controlled trial.
abstract: OBJECTIVE
  The purposes of this study were: (1) to assess the effectiveness of a 16-week progressive program of home-based, videotape-based, low-impact aerobic exercise on physical function and signs and symptoms of fibromyalgia in previously sedentary women aged 20 to 55 years and (2) to compare the effects of 1 long exercise bout versus 2 short exercise bouts per training day (fractionation) on physical function, signs and symptoms of fibromyalgia, and exercise adherence.
  
  
  METHODS
  One hundred forty-three sedentary women were randomly assigned to 1 of 3 groups: a group who trained using a long bout of exercise (LBE group, n=51), a group who trained using short bouts of exercise (SBE group, n=56), and a group who performed no exercise (NE group, n=36).
  
  
  METHODS
  The SBE group exercised twice daily, and the LBE group worked out once daily. Both groups progressed in total daily training duration from 10 to 30 minutes, 3 to 5 times a week, for 16 weeks. Physical and psychological well-being, symptoms, and self-efficacy were evaluated using a multivariate analysis of variance.
  
  
  RESULTS
  Dropout rates for the NE, SBE, and LBE groups were 14%, 38%, and 29%, respectively. The NE group differed from the LBE group in disease severity, self-efficacy, and psychological well-being (midtest, efficacy analysis) and from the SBE group in disease severity and self-efficacy (posttest, efficacy analysis). Exercise adherence was greater for the LBE group than for the SBE group between weeks 5 and 8 of the training program. No other differences between exercise groups were found.
  
  
  CONCLUSIONS
  Progressive, home-based, low-impact aerobics improved physical function and fibromyalgia symptoms minimally in participants who completed at least two thirds of the recommended exercise. Fractionation of exercise training provided no advantage in terms of exercise adherence, improvements in fibromyalgia symptoms or physical function. High attrition rates and problems with exercise adherence were experienced in both exercise groups.
authors.affiliation: School of Physical Therapy, University of Saskatchewan, 1121 College Dr, Saskatoon, Saskatchewan, S7N 0W3 Canada. schachter@usask.ca
authors.forename: Candice L
authors.initials: CL
authors.lastname: Schachter
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Busch
authors.forename: Paul M
authors.initials: PM
authors.lastname: Peloso
authors.forename: M Suzanne
authors.initials: MS
authors.lastname: Sheppard
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015444:Exercise; D005260:Female; D005356:Fibromyalgia / Q000534:rehabilitation*; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D010349:Patient Compliance; D010352:Patient Dropouts; D012525:Saskatchewan; D020377:Self Efficacy; D013997:Time Factors