title: Quantifying the acute changes in glucose with exercise in type 1 diabetes: a systematic review and meta-analysis.
abstract: BACKGROUND
  The acute impact of different types of physical activity on glycemic control in type 1 diabetes has not been well quantified.
  
  
  OBJECTIVE
  Our objective was to estimate the rate of change (RoC) in glucose concentration induced acutely during the performance of structured exercise and at recovery in subjects with type 1 diabetes.
  
  
  METHODS
  We searched for original articles in the PubMed, MEDLINE, Scopus, and Cochrane databases. Search terms included type 1 diabetes, blood glucose, physical activity, and exercise. Eligible studies (randomized controlled trials and non-randomized experiments) encompassed controlled physical activity sessions (continuous moderate [CONT], intermittent high intensity [IHE], resistance [RESIST], and/or a resting reference [REST]) and reported excursions in glucose concentration during exercise and after its cessation. Data were extracted by graph digitization to compute two RoC measures from population profiles: RoCE during exercise and RoCR in recovery.
  
  
  RESULTS
  Ten eligible studies were found from 540 publications. Meta-analyses of exercise modalities versus rest yielded the following: RoCE -4.43 mmol/L h(-1) (p < 0.00001, 95% confidence interval [CI] -6.06 to -2.79) and RoCR +0.70 mmol/L h(-1) (p = 0.46, 95% CI -1.14 to +2.54) for CONT vs. REST; RoCE -5.25 mmol/L·h(-1) (p < 0.00001, 95 % CI -7.02 to -3.48) and RoCR +0.72 mmol/L h(-1) (p = 0.71, 95% CI -3.10 to +4.54) for IHE vs. REST; RoCE -2.61 mmol/L h(-1) (p = 0.30, 95% CI -7.55 to +2.34) and RoCR -0.02 mmol/L h(-1) (p = 1.00, 95% CI -7.58 to +7.53) for RESIST vs. REST.
  
  
  CONCLUSIONS
  Novel RoC magnitudes RoCE, RoCR reflected rapid decays of glycemia during CONT exercise and gradual recoveries immediately afterwards. RESIST showed more constrained decays, whereas discrepancies were found for IHE.
authors.affiliation: Bioengineering and Telemedicine Group, Universidad Politécnica de Madrid, Madrid, Spain, fgarcia@gbt.tfo.upm.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: García-García
authors.forename: Kavita
authors.initials: K
authors.lastname: Kumareswaran
authors.forename: Roman
authors.initials: R
authors.lastname: Hovorka
authors.forename: M Elena
authors.initials: ME
authors.lastname: Hernando
mesh_terms: D001786:Blood Glucose / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D055070:Resistance Training
chemical_list: D001786:Blood Glucose