title: Estimating cardiorespiratory fitness in well-functioning older adults: treadmill validation of the long distance corridor walk.
abstract: OBJECTIVE
  To determine criterion validity of the 400-m walk component of the Long Distance Corridor Walk (LDCW) and develop equations for estimating peak oxygen consumption (VO2) from 400-m time and factors intrinsic to test performance (e.g., heart rate (HR) and systolic blood pressure (SBP) response) in older adults.
  
  
  METHODS
  Cross-sectional validation study.
  
  
  METHODS
  Gerontology Research Center, National Institute on Aging, Baltimore, Maryland.
  
  
  METHODS
  Healthy volunteers (56 men and 46 women) aged 60 to 91 participating in the Baltimore Longitudinal Study of Aging between August 1999 and July 2000.
  
  
  METHODS
  The LDCW, consisting of a 2-minute walk followed immediately by a 400-m walk "done as quickly as possible" over a 20-m course was administered the day after maximal treadmill testing. HR and SBP were measured before testing and at the end of the 400-m walk. Weight, height, activity level, perceived effort, and stride length were also acquired.
  
  
  RESULTS
  Peak VO2 ranged from 12.2 to 31.1 mL oxygen/kg per minute, and 400-m time ranged from 2 minutes 52 seconds to 6 minutes 18 seconds. Correlation between 400-m time and peak VO2 was -0.79. The estimating equation from linear regression included 400-m time (partial coefficient of determination (R2)=0.625), long versus short stride (partial R2=0.090), ending SBP (partial R2=0.019), and a correction factor for fast 400-m time (<240 seconds; partial R2=0.020) and explained 75.5% of the variance in peak VO2 (correlation coefficient=0.87).
  
  
  CONCLUSIONS
  A 400-m walk performed as part of the LDCW provides a valid estimate of peak VO2 in older adults. Incorporating low-cost, safe assessments of fitness in clinical and research settings can identify early evidence of physical decline and individuals who may benefit from therapeutic interventions.
authors.affiliation: Clinical Research Branch, National Institute on Aging, Baltimore, Maryland 21225, USA. simonsickel@mail.nih.gov
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
authors.forename: Ellen
authors.initials: E
authors.lastname: Fan
authors.forename: Jerome L
authors.initials: JL
authors.lastname: Fleg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001794:Blood Pressure / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012143:Respiratory Physiological Phenomena; D016138:Walking / Q000502:physiology*