title: How fast do we age? Exercise performance over time as a biomarker.
abstract: BACKGROUND
  The rate of true chronologic functional change in humans has been previously obscured by inadvertent inclusion of data derived from sick or ill-conditioned individuals. The Masters athlete fulfills the need for a study cohort.
  
  
  METHODS
  Performance data by age were collected from recognized certifying organizations for running, rowing, and swimming events and plotted as percent decline from age 35, and a rate of decline of performance by age was plotted.
  
  
  RESULTS
  Close coincidence of the decay slopes of the events surveyed was observed. This rate is 0.5% per year. We argue that inasmuch as these strenuous events are subtended by most of the major body systems and are thereby rate-limited by them all, that no supporting system can decline faster than this rate.
  
  
  CONCLUSIONS
  The virtual identity of the performance slopes of the different athletic events with one another and to that of other functions including that of a central physiologic measure, VO2 max, indicates that 0.5% per year may be a basic biomarker of the aging process.
authors.affiliation: Department of Medicine, University of North Carolina Medical Center, Chapel Hill, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Bortz
authors.forename: W M
authors.initials: WM
authors.lastname: Bortz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance; D013997:Time Factors