title: Smaller age-associated reductions in leg venous compliance in endurance exercise-trained men.
abstract: We determined the independent and interactive influences of aging and habitual endurance exercise on calf venous compliance in humans. We tested the hypotheses that calf venous compliance is 1) reduced with age in sedentary and endurance-trained men, and 2) elevated in young and older endurance-trained compared with age-matched sedentary men. We studied 8 young (28 +/- 1 yr) and 8 older (65 +/- 1) sedentary, and 8 young (27 +/- 1) and 8 older (63 +/- 2) endurance-trained men. Calf venous compliance was measured in supine subjects by inflating a venous collecting cuff, placed above the knee, to 60 mmHg for 8 min and then decreasing cuff pressure at 1 mmHg/s to 0 mmHg. Calf venous compliance was determined using the first derivative of the pressure-volume relation during cuff pressure reduction (compliance = beta(1) + 2. beta(2). cuff pressure). Calf venous compliance was reduced with age in sedentary (approximately 40%) and endurance-trained men (approximately 20%) (both P < 0.01). Furthermore, calf venous compliance was approximately 70-120% greater in endurance-trained compared with age-matched sedentary men and approximately 30% greater in older endurance-trained compared with young sedentary men (both P < 0.01). These data indicate that calf venous compliance is reduced with age in sedentary and endurance-trained men, but compliance is better preserved in endurance-trained men.
authors.affiliation: Human Cardiovascular Research Laboratory, Center for Physical Activity, Disease Prevention, and Aging, Department of Kinesiology and Applied Physiology, University of Colorado at Boulder, Boulder, Colorado 80309, USA.
authors.forename: K D
authors.initials: KD
authors.lastname: Monahan
authors.forename: F A
authors.initials: FA
authors.lastname: Dinenno
authors.forename: D R
authors.initials: DR
authors.lastname: Seals
authors.forename: J R
authors.initials: JR
authors.lastname: Halliwill
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D003187:Compliance; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000098:blood supply* / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010991:Plethysmography; D011187:Posture / Q000502:physiology; D012420:Running / Q000502:physiology; D014680:Veins / Q000502:physiology*