title: Preliminary findings in the heart rate variability and haemorheology response to varied frequency and duration of walking in women 65-74 yr with type 2 diabetes.
abstract: Heart rate variability (HRV) and haemorheology adaptations to 12 wk of varied-dose treadmill walking were investigated in women aged 65-74 yr with type 2 diabetes. Subjects were randomly allocated into two groups where exercise frequency and session duration were manipulated (Group 1: 2 × 60 min·wk(-1) or Group 2: 4 × 30 min·wk(-1)), but intensity and accumulated weekly duration of exercise were consistent between groups (100% gas-exchange threshold; 120 min·wk(-1)). Twelve weeks of exercise training significantly improved peak oxygen uptake, time to exhaustion, and gas-exchange threshold (p < 0.05), independent of exercise group. Exercise training did not significantly change glycaemic control or body mass. Red blood cell (RBC) aggregation and RBC deformability significantly decreased (p < 0.05) for both groups. No change in HRV was observed for Group 1, whereas several key indicators of HRV were significantly improved in Group 2 (p < 0.05). The present study was the first to report decreased RBC aggregation following an exercise-only intervention and that exercise training improved RBC aggregation without a concomitant improvement in glycaemic control. The accumulated weekly exercise duration may be the most important training component for the prescription of exercise in older women with type 2 diabetes.
authors.affiliation: Heart Foundation Research Centre, Griffith University, Gold Coast, QLD, Australia. misimmon@bond.edu.au
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Simmonds
authors.forename: Clare L
authors.initials: CL
authors.lastname: Minahan
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Serre
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Gass
authors.forename: Sonya M
authors.initials: SM
authors.lastname: Marshall-Gradisnik
authors.forename: Luke J
authors.initials: LJ
authors.lastname: Haseler
authors.forename: Surendran
authors.initials: S
authors.lastname: Sabapathy
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D004903:Erythrocyte Aggregation; D004907:Erythrocyte Deformability; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D018056:Hemorheology; D006801:Humans; D010101:Oxygen Consumption / Q000502:physiology; D016138:Walking / Q000502:physiology*