Ventilatory threshold may be a more specific measure of aerobic capacity than peak oxygen consumption rate in persons with stroke

Top Stroke Rehabil. 2017 Mar;24(2):149-157. doi: 10.1080/10749357.2016.1209831. Epub 2016 Jul 25.


Background: 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.

Objectives: 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.

Methods: 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).

Results: 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).

Conclusions: 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.

Keywords: Aerobic capacity; Deconditioning; Exercise testing; Motor function; Paresis; Stroke.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cross-Sectional Studies
  • Exercise*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Movement Disorders / etiology*
  • Oxygen Consumption / physiology*
  • Reproducibility of Results
  • Severity of Illness Index
  • Statistics as Topic
  • Stroke / complications*
  • Stroke Rehabilitation / methods*