title: Comparison of the effect of multiple short-duration with single long-duration exercise sessions on glucose homeostasis in type 2 diabetes mellitus.
abstract: OBJECTIVE
  We evaluated and compared the effects on glycaemic control of two different exercise protocols in elderly men with type 2 diabetes mellitus.
  
  
  METHODS
  Eighteen patients with type 2 diabetes mellitus carried out home-based bicycle training for 5 weeks. Patients were randomly assigned to one of two training programmes at 60% of maximal oxygen uptake: three 10 min sessions per day (3 x 10) or one 30 min session per day (1 x 30). Plasma insulin, C-peptide and glucose concentrations were measured during a 3 h oral glucose tolerance test (OGTT). Insulin sensitivity index (ISI(composite)), pre-hepatic insulin secretion rates (ISR) and change in insulin secretion per unit change in glucose concentrations (B(total)) were calculated.
  
  
  RESULTS
  Cardiorespiratory fitness increased in response to training in both groups. In group 3 x 10 (n = 9) fasting plasma glucose (p = 0.01), 120 min glucose OGTT (p = 0.04) and plasma glucose concentration areas under the curve at 120 min (p < 0.04) and 180 min (p = 0.07) decreased. These parameters remained unchanged in group 1 x 30 (n = 9). No significant changes were found in ISI(composite), ISR and B(total) in either of the exercise groups. In a matched time-control group (n = 10), glycaemic control did not change.
  
  
  CONCLUSIONS
  Moderate to high-intensity training performed at 3 x 10 min/day is preferable to 1 x 30 min/day with regard to effects on glycaemic control. This is in spite of the fact that cardiorespiratory fitness increased similarly in both exercise groups. A possible explanation is that the energy expenditure associated with multiple short daily sessions may be greater than that in a single daily session.
authors.affiliation: Department of Biomedical Sciences, The Copenhagen Muscle Research Centre, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Eriksen
authors.forename: I
authors.initials: I
authors.lastname: Dahl-Petersen
authors.forename: S B
authors.initials: SB
authors.lastname: Haugaard
authors.forename: F
authors.initials: F
authors.lastname: Dela
mesh_terms: D017668:Age of Onset; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure; D002096:C-Peptide / Q000097:blood; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D007328:Insulin / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D010349:Patient Compliance; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D008074:Lipoproteins; D002784:Cholesterol