title: Three 15-min bouts of moderate postmeal walking significantly improves 24-h glycemic control in older people at risk for impaired glucose tolerance.
abstract: OBJECTIVE
  The purpose of this study was to compare the effectiveness of three 15-min bouts of postmeal walking with 45 min of sustained walking on 24-h glycemic control in older persons at risk for glucose intolerance.
  
  
  METHODS
  Inactive older (≥60 years of age) participants (N=10) were recruited from the community and were nonsmoking, with a BMI<35 kg/m2 and a fasting blood glucose concentration between 105 and 125 mg dL(-1). Participants completed three randomly ordered exercise protocols spaced 4 weeks apart. Each protocol comprised a 48-h stay in a whole-room calorimeter, with the first day serving as the control day. On the second day, participants engaged in either 1) postmeal walking for 15 min or 45 min of sustained walking performed at 2) 10:30 a.m. or 3) 4:30 p.m. All walking was on a treadmill at an absolute intensity of 3 METs. Interstitial glucose concentrations were determined over 48 h with a continuous glucose monitor. Substrate utilization was measured continuously by respiratory exchange (VCO2/VO2).
  
  
  RESULTS
  Both sustained morning walking (127±23 vs. 118±14 mg dL(-1)) and postmeal walking (129±24 vs. 116±13 mg dL(-1)) significantly improved 24-h glycemic control relative to the control day (P<0.05). Moreover, postmeal walking was significantly (P<0.01) more effective than 45 min of sustained morning or afternoon walking in lowering 3-h postdinner glucose between the control and experimental day.
  
  
  CONCLUSIONS
  Short, intermittent bouts of postmeal walking appear to be an effective way to control postprandial hyperglycemia in older people.
authors.affiliation: Corresponding author: Loretta DiPietro, ldp1@gwu.edu.
authors.forename: Loretta
authors.initials: L
authors.lastname: DiPietro
authors.forename: Andrei
authors.initials: A
authors.lastname: Gribok
authors.forename: Michelle S
authors.initials: MS
authors.lastname: Stevens
authors.forename: Larry F
authors.initials: LF
authors.lastname: Hamm
authors.forename: William
authors.initials: W
authors.lastname: Rumpler
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D018149:Glucose Intolerance / Q000517:prevention & control*; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period / Q000502:physiology; D016138:Walking / Q000502:physiology*
chemical_list: D001786:Blood Glucose