title: Longitudinal assessment of the effect of age and experience on performance in 161-km ultramarathons.
abstract: OBJECTIVE
  This work longitudinally assesses the influence of aging and experience on time to complete 161-km ultramarathons.
  
  
  METHODS
  From 29,331 finishes by 4066 runners who had completed 3 or more 161-km ultramarathons in North America from 1974 through 2010, independent cohorts of men (n = 3,092), women (n = 717), and top-performing men (n = 257) based on age-group finish place were identified. Linear mixed-effects regression was used to assess the effects of aging and previous 161-km finish number on finish time adjusted for the random effects of runner, event, and year.
  
  
  RESULTS
  Men and women up to 38 y of age slowed by 0.05-0.06 h/y with advancing age. Men slowed 0.17 h/y from 38 through 50 y and 0.23 h/y after 50 y. Women slowed 0.20-0.23 h/y with advancing age from 38 y. Top-performing men under 38 y did not slow with increasing age but slowed by 0.26 and 0.39 h/y from 38 through 50 y and after 50 y, respectively. Finish number was inversely associated with finish time for all 3 cohorts. A 10th or higher finish was 1.3, 1.7, and almost 3 h faster than a first finish for men, women, and top-performing men, respectively.
  
  
  CONCLUSIONS
  High-level performances in 161-km ultramarathoners can be sustained late into the 4th decade of life, but subsequent aging is associated with declines in performance. Nevertheless, the adverse effects of aging on performance can be offset by greater experience in these events.
authors.affiliation: Dept of Physical Medicine & Rehabilitation, Dept of Veterans Affairs, Northern California Health Care System, and University of California Davis Medical Center, Sacramento, CA.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Hoffman
authors.forename: Carol A
authors.initials: CA
authors.lastname: Parise
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D003163:Competitive Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology*; D012420:Running / Q000502:physiology*