title: Age-specific normal values for the incremental shuttle walk test in a healthy British population.
abstract: OBJECTIVE
  The Incremental Shuttle Walk Test (ISWT) is an important functional and prognostic marker in chronic disease. Aging has a detrimental effect on exercise performance. The objective of this study was to produce normal age-specific values for the ISWT in a healthy British population and to explore whether additional variables improve the accuracy of a predictive equation.
  
  
  METHODS
  Healthy subjects (N = 152), aged 40 to 90 years, were recruited. Data collection occurred over 2 study visits. Anthropometric and demographic data were collected, and lung function and quadriceps maximal voluntary contraction were measured. An accelerometer was worn for 2 consecutive days at home. The Duke Activity Status Index was completed, and the greatest distance from 2 ISWTs was recorded.
  
  
  RESULTS
  One hundred forty subjects (56 men) with mean age (SD) of 59.4 (11.0) years completed 2 ISWTs. Forced expiratory volume in 1 second (FEV(1)) was 109.1% (14.56%) predicted and ISWT distance was 737 m (183 m). Age-specific normal values for the ISWT were observed: mean (lower limit of normal)--40 to 49 years, 824 m (765 m); 50 to 59 years, 788 m (730 m); 60 to 69 years, 699 m (649 m); and 70 years and older, 633 m (562 m). A predictive equation was developed from 114 subjects. Age, body mass index, FEV(1), quadriceps maximal voluntary contraction, and Duke Activity Status Index contributed to ISWT distance predicting 50.4% of the variation in performance.
  
  
  CONCLUSIONS
  We have developed age-specific normal values for performance on the ISWT in a healthy British population. However, even using practical, clinically relevant variables, it is not possible to accurately predict exercise capacity from a regression equation.
authors: Pulmonary Rehabilitation Research Group, University Hospitals of Leicester National Health Service Trust, Glenfield Hospital, Leicester, United Kingdom. samantha.harrison@uhl-tr.nhs.uk
authors: Samantha Louise
authors: SL
authors: Harrison
authors: Neil J
authors: NJ
authors: Greening
authors: Linzy
authors: L
authors: Houchen-Wolloff
authors: John
authors: J
authors: Bankart
authors: Mike D L
authors: MD
authors: Morgan
authors: Michael C
authors: MC
authors: Steiner
authors: Sally J
authors: SJ
authors: Singh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D012016:Reference Values; D013147:Spirometry; D006113:United Kingdom; D016138:Walking / Q000502:physiology*