title: Evidence of an association among age-related changes in physical, psychomotor and autonomic function.
abstract: BACKGROUND
  autonomic modulation of the heart, as measured by heart rate variability, is directly associated with cardiorespiratory fitness and inversely associated with all-cause mortality. The extent to which cardiorespiratory fitness and heart rate variability are related in older adults is difficult to ascertain due to difficulties in assessing physical fitness among older age groups.
  
  
  OBJECTIVE
  to examine heart rate variability and measures of physical function, thereby allowing for the inclusion of a greater cross-section of older adults than can be tested using traditional fitness tests.
  
  
  METHODS
  39 older adults (mean age: 73.2+/-8.1 years; range=60-93 years) underwent evaluation of short-term (5 min) heart rate variability and performance of the American Alliance for Health Physical Education Recreation and Dance Functional Fitness Assessment for Older Adults. Pearson correlation, stepwise multiple regression, and factor analysis were used to describe associations among age, heart rate variability, and functional fitness test-items.
  
  
  RESULTS
  significant associations were observed for age and the standard deviation of all normal RR intervals (r=-0.39, P<0.01), and the American Alliance for Health Physical Education Recreation and Dance cardiovascular endurance (r=0.45, P<0.01), strength (r=-0.53, P<0.001), agility (r=0.80, P<0.001), and coordination (r=0.57, P<0.001) items. Standard deviation of all normal RR intervals was negatively associated with the American Alliance for Health Physical Education Recreation and Dance agility (r=-0.37, P<0.01) and coordination (r=-0.49, P<0.001) items. Stepwise multiple regression included only the American Alliance for Health Physical Education Recreation and Dance coordination performance in predicting standard deviation of all normal RR intervals [standard deviation=63.98-2.5 (coordination), F=33.9, P<0.01]. Factor analysis revealed that age, agility, and coordination comprised one factor with a high degree of commonality.
  
  
  CONCLUSIONS
  the association between heart rate variability and coordination suggests concurrent aging of autonomic and psychomotor function.
authors.affiliation: Louisiana State University, Department of Kinesiology, 112 Long Fieldhouse, Baton Rouge, LA 70803, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Wood
authors.forename: Jan M
authors.initials: JM
authors.lastname: Hondzinski
authors.forename: C Matthew
authors.initials: CM
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001341:Autonomic Nervous System / Q000502:physiology*; D016000:Cluster Analysis; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D008168:Lung / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D011597:Psychomotor Performance / Q000502:physiology*; D012119:Respiration