title: Physical activity duration, intensity, and arterial stiffening in postmenopausal women.
abstract: BACKGROUND
  Aerobic exercise training is associated with lower central arterial stiffness, but little information exists on the effects of physical activity intensity or duration on central arterial stiffness. Using a cross-sectional and interventional approach, we tested the hypothesis that both moderate and vigorous physical activity reduce central arterial stiffness in postmenopausal women.
  
  
  METHODS
  Carotid arterial stiffness (via ultrasound and applanation tonometry) and duration of physical activity at low, moderate, and vigorous intensities (via electronic accelerometer) were measured in 103 apparently healthy sedentary or recreationally active women 47 to 82 years of age. Moderate intensity physical activity was defined as 4.0 to 6.0 metabolic equivalents (MET) in subjects aged <65 years and as 3.0 to 5.0 MET in subjects >or=65 years. A subgroup of 17 sedentary subjects was randomly assigned to moderate (n = 8) or vigorous (n = 9) intensity cycling exercise training (900 kcal/week, three to five sessions per week, for 12 weeks). Carotid arterial stiffness was measured before and after training.
  
  
  RESULTS
  Carotid beta-stiffness index was significantly correlated with the duration of moderate and vigorous intensity physical activity (r = -0.25 and r = -0.22) even after adjustment for age, height, and mean BP. Carotid beta-stiffness index significantly decreased after moderate and vigorous intensity cycling training. There were no significant group differences in the magnitude of beta-stiffness index change even after adjustment for expected confounders (eg, baseline beta-stiffness index, height, body mass index, heart rate, and post-training body mass, body mass index, and mean BP).
  
  
  CONCLUSIONS
  These results suggest that both moderate and vigorous physical activities have favorable effects on central arterial stiffness in postmenopausal women.
authors.affiliation: Institute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan. jun.sugawara@aist.go.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Sugawara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Otsuki
authors.forename: Takumi
authors.initials: T
authors.lastname: Tanabe
authors.forename: Koichiro
authors.initials: K
authors.lastname: Hayashi
authors.forename: Seiji
authors.initials: S
authors.lastname: Maeda
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Matsuda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000503:physiopathology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004548:Elasticity; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D017698:Postmenopause / Q000502:physiology*; D012720:Severity of Illness Index; D014463:Ultrasonography; D014655:Vascular Resistance / Q000502:physiology