title: A systematic review and meta-analysis of exercise interventions in adults with type 1 diabetes.
abstract: OBJECTIVE
  Conflicting evidence exists regarding the benefits of physical activity for long-term blood glucose control in adults with type 1 diabetes (T1D). The object of this systematic review was to determine the effects of physical activity on long-term blood glucose control in T1D adults.
  
  
  METHODS
  PubMed/Medline, Embase, CENTRAL, SPORTdiscus, Global Health and ICTRP were searched up to October 2013 for randomized trials of aerobic or resistance exercise training in T1D adults. Exercises had to be performed at least twice weekly for a minimum of two months. The primary outcome was glycated hemoglobin (HbA1c). Secondary outcomes included cardiorespiratory fitness and insulin dose.
  
  
  RESULTS
  Six randomized trials were identified (323 adults); sample sizes ranged from n=6 to n=148 participants receiving the intervention. Five trials had an unknown risk of bias; one trial was deemed to be at high risk of bias. Exercise frequency varied from twice weekly to daily, with intensities (50-90% VO2peak), and session durations (20-120 min) varying widely. Four trials reported HbA1c, which decreased with exercise training (mean difference [MD] -0.78% (-9 mmol/mol), 95% CI -1.14 (-13 mmol/mol) to -0.41 (-5 mmol/mol); p<0.0001; I(2) 0%) compared with controls. Exercise training improved cardiorespiratory fitness by 3.45 ml/kg/min (95% CI 0.59 to 6.31, p=0.02, I(2) 0%) compared with controls. One trial reported an effect on insulin dose (MD -0.4U/kg, 95% CI -0.53 to -0.27, p<0.00001) compared to controls.
  
  
  CONCLUSIONS
  There are currently insufficient well-designed studies to ascertain the true effect of exercise training on HbA1c in individuals with T1D, but current results are promising.
authors.affiliation: Manitoba Institute of Child Health, University of Manitoba, Winnipeg, MB, Canada; University of Alberta, Augustana Campus, Camrose, AB, Canada.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Yardley
authors.affiliation: Manitoba Institute of Child Health, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Hay
authors.affiliation: George & Fay Yee Centre for Healthcare Innovation, University of Manitoba, Winnipeg, MB, Canada; Winnipeg Regional Health Authority, Winnipeg, MB, Canada.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Abou-Setta
authors.affiliation: Department of Pediatrics, University of Manitoba, Winnipeg, MB, Canada.
authors.forename: Seth D
authors.initials: SD
authors.lastname: Marks
authors.affiliation: Manitoba Institute of Child Health, University of Manitoba, Winnipeg, MB, Canada. Electronic address: jmcgavock@mich.ca.
authors.forename: Jonathan
authors.initials: J
authors.lastname: McGavock
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000534:rehabilitation*; D005081:Exercise Therapy / Q000379:methods*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006304:Health Status; D006801:Humans; D055070:Resistance Training / Q000379:methods*
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin
keywords: Glycemic control; Physical activity; Type 1 diabetes