title: Ventilatory threshold may be a more specific measure of aerobic capacity than peak oxygen consumption rate in persons with stroke.
abstract: After stroke, aerobic deconditioning can have a profound impact on daily activities. This is usually measured by the peak oxygen consumption rate achieved during exercise testing (VO2-peak). However, VO2-peak may be distorted by motor function. The oxygen uptake efficiency slope (OUES) and VO2 at the ventilatory threshold (VO2-VT) could more specifically assess aerobic capacity after stroke, but this has not been tested.
  
  
  
  To assess the differential influence of motor function on three measures of aerobic capacity (VO2-peak, OUES, and VO2-VT) and to evaluate the inter-rater reliability of VO2-VT determination post-stroke.
  
  
  
  Among 59 persons with chronic stroke, cross-sectional correlations with motor function (comfortable gait speed [CGS] and lower extremity Fugl-Meyer [LEFM]) were compared between the different aerobic capacity measures, after adjustment for covariates, in order to isolate any distorting effect of motor function. Reliability of VO2-VT determination between three raters was assessed with intra-class correlation (ICC).
  
  
  
  CGS was moderately correlated with VO2-peak (r = 0.52, p < 0.0001) and weakly correlated with OUES (r = 0.41, p = 0.002) and VO2-VT (r = 0.37, p = 0.01). LEFM was weakly correlated with VO2-peak (r = 0.26, p = 0.055) and very weakly correlated with OUES (r = 0.19, p = 0.17) and VO2-VT (r = 0.14, p = 0.31). Compared to VO2-peak, VO2-VT was significantly less correlated with CGS (r difference = -0.16, p = 0.02). Inter-rater reliability of VO2-VT determination was high (ICC: 0.93, 95% CI: 0.89-0.96).
  
  
  
  Motor dysfunction appears to artificially lower measured aerobic capacity. VO2-VT seemed to be less distorted than VO2-peak and had good inter-rater reliability, so it may provide more specific assessment of aerobic capacity post-stroke.
authors.affiliation: a Department of Rehabilitation Sciences , College of Allied Health Sciences, University of Cincinnati , Cincinnati , OH , USA.|b Department of Environmental Health , College of Medicine, University of Cincinnati , Cincinnati , OH , USA.
authors.forename: Pierce
authors.initials: P
authors.lastname: Boyne
authors.affiliation: c Department of Physical Therapy , College of Health Sciences, University of Delaware , Newark , DE , USA.
authors.forename: Darcy
authors.initials: D
authors.lastname: Reisman
authors.affiliation: c Department of Physical Therapy , College of Health Sciences, University of Delaware , Newark , DE , USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Brian
authors.affiliation: a Department of Rehabilitation Sciences , College of Allied Health Sciences, University of Cincinnati , Cincinnati , OH , USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Barney
authors.affiliation: a Department of Rehabilitation Sciences , College of Allied Health Sciences, University of Cincinnati , Cincinnati , OH , USA.
authors.forename: Ava
authors.initials: A
authors.lastname: Franke
authors.affiliation: a Department of Rehabilitation Sciences , College of Allied Health Sciences, University of Cincinnati , Cincinnati , OH , USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Carl
authors.affiliation: b Department of Environmental Health , College of Medicine, University of Cincinnati , Cincinnati , OH , USA.|d Division of Biostatistics and Epidemiology , Cincinnati Children's Hospital Medical Center , Cincinnati , OH , USA.
authors.forename: Jane
authors.initials: J
authors.lastname: Khoury
authors.affiliation: a Department of Rehabilitation Sciences , College of Allied Health Sciences, University of Cincinnati , Cincinnati , OH , USA.|b Department of Environmental Health , College of Medicine, University of Cincinnati , Cincinnati , OH , USA.
authors.forename: Kari
authors.initials: K
authors.lastname: Dunning
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology*; D010101:Oxygen Consumption / Q000502:physiology*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013223:Statistics as Topic; D020521:Stroke / Q000150:complications*; D000071939:Stroke Rehabilitation / Q000379:methods*
keywords: Aerobic capacity; Deconditioning; Exercise testing; Motor function; Paresis; Stroke