title: Impact of lifelong exercise "dose" on left ventricular compliance and distensibility.
abstract: BACKGROUND
  Sedentary aging has deleterious effects on the cardiovascular system, including decreased left ventricular compliance and distensibility (LVCD). Conversely, Masters level athletes, who train intensively throughout adulthood, retain youthful LVCD.
  
  
  OBJECTIVE
  The purpose of this study was to test the hypothesis that preservation of LVCD may be possible with moderate lifelong exercise training.
  
  
  METHODS
  Healthy seniors (n = 102) were recruited from predefined populations, screened for lifelong patterns of exercise training, and stratified into 4 groups: "sedentary" (<2 sessions/week); "casual" (2 to 3 sessions/week); "committed" (4 to 5 sessions/week); and "competitive" Masters level athletes (6 to 7 sessions/week). Right heart catheterization and echocardiography were performed while preload was manipulated using lower body negative pressure and rapid saline infusion to define LV pressure-volume relationships and Frank-Starling curves.
  
  
  RESULTS
  Peak oxygen uptake and LV mass increased with escalating doses of lifelong exercise, with little change in systolic function. At baseline, LV distensibility was greater in committed (21%) and competitive (36%) exercisers than in sedentary subjects. Group LV stiffness constants (sedentary: 0.062 ± 0.039; casual: 0.079 ± 0.052; committed: 0.055 ± 0.033; and competitive: 0.035 ± 0.033) revealed: 1) increased stiffness in sedentary subjects compared to competitive athletes, whereas lifelong casual exercise had no effect; and 2) greater compliance in committed exercisers than in sedentary or casual exercisers.
  
  
  CONCLUSIONS
  Low doses of casual, lifelong exercise do not prevent the decreased compliance and distensibility observed with healthy, sedentary aging. In contrast, 4 to 5 exercise sessions/week throughout adulthood prevent most of these age-related changes. As LV stiffening has been implicated in the pathophysiology of many cardiovascular conditions affecting the elderly, this "dose" of exercise training may have important implications for prevention of cardiovascular disease.
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas; John Peter Smith Health Network, Fort Worth, Texas.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Bhella
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Hastings
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas.
authors.forename: Naoki
authors.initials: N
authors.lastname: Fujimoto
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas.
authors.forename: Graeme
authors.initials: G
authors.lastname: Carrick-Ranson
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas.
authors.forename: M Dean
authors.initials: MD
authors.lastname: Palmer
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas.
authors.forename: Kara N
authors.initials: KN
authors.lastname: Boyd
authors.affiliation: University of Texas-Southwestern Medical Center at Dallas, Dallas, Texas.
authors.forename: Beverley
authors.initials: B
authors.lastname: Adams-Huet
authors.affiliation: Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas; University of Texas-Southwestern Medical Center at Dallas, Dallas, Texas. Electronic address: BenjaminLevine@TexasHealth.org.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Levine
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D056352:Athletes; D006328:Cardiac Catheterization / Q000379:methods; D015331:Cohort Studies; D003187:Compliance / Q000502:physiology; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D040242:Risk Reduction Behavior; D057185:Sedentary Behavior; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: aging; diastolic function; distensibility; exercise training; hemodynamics; ventricular compliance