title: Alterations in Aerobic Exercise Performance and Gait Economy Following High-Intensity Dynamic Stepping Training in Persons With Subacute Stroke.
abstract: OBJECTIVE
  Impairments in metabolic capacity and economy (O2cost) are hallmark characteristics of locomotor dysfunction following stroke. High-intensity (aerobic) training has been shown to improve peak oxygen consumption in this population, with fewer reports of changes in O2cost. However, particularly in persons with subacute stroke, inconsistent gains in walking function are observed with minimal associations with gains in metabolic parameters. The purpose of this study was to evaluate changes in aerobic exercise performance in participants with subacute stroke following high-intensity variable stepping training as compared with conventional therapy.
  
  
  METHODS
  A secondary analysis was performed on data from a randomized controlled trial comparing high-intensity training with conventional interventions, and from the pilot study that formed the basis for the randomized controlled trial. Participants 1 to 6 months poststroke received 40 or fewer sessions of high-intensity variable stepping training (n = 21) or conventional interventions (n = 12). Assessments were performed at baseline (BSL), posttraining, and 2- to 3-month follow-up and included changes in submaximal (Equation is included in full-text article.)O2 ((Equation is included in full-text article.)O2submax) and O2cost at fastest possible treadmill speeds and peak speeds at BSL testing.
  
  
  RESULTS
  Significant improvements were observed in (Equation is included in full-text article.)O2submax with less consistent improvements in O2cost, although individual responses varied substantially. Combined changes in both (Equation is included in full-text article.)O2submax and (Equation is included in full-text article.)O2 at matched peak BSL speeds revealed stronger correlations to improvements in walking function as compared with either measure alone.
  
  
  CONCLUSIONS
  High-intensity stepping training may elicit significant improvements in (Equation is included in full-text article.)O2submax, whereas changes in both peak capacity and economy better reflect gains in walking function. Providing high-intensity training to improve locomotor and aerobic exercise performance may increase the efficiency of rehabilitation sessions.Video Abstract available for more insights from the authors (see Supplemental Digital Content, http://links.lww.com/JNPT/A142).
authors.affiliation: Sensory Motor Performance Program (A.L.L., M.C., C.L.H., P.W.H., J.W., T.G.H.), Rehabilitation Institute of Chicago, Chicago, Illinois; Department of Physical Medicine and Rehabilitation (R.A.A., E.J.R., T.G.H.), Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Department of Physical Therapy and Kinesiology & Nutrition (R.A.A.), University of Illinois at Chicago; and Department of Physical Medicine and Rehabilitation (T.G.H.), Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Abigail L
authors.initials: AL
authors.lastname: Leddy
authors.forename: Mark
authors.initials: M
authors.lastname: Connolly
authors.forename: Carey L
authors.initials: CL
authors.lastname: Holleran
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Hennessy
authors.forename: Jane
authors.initials: J
authors.lastname: Woodward
authors.forename: Ross A
authors.initials: RA
authors.lastname: Arena
authors.forename: Elliot J
authors.initials: EJ
authors.lastname: Roth
authors.forename: T George
authors.initials: TG
authors.lastname: Hornby
mesh_terms: D015444:Exercise; D005080:Exercise Test; D005081:Exercise Therapy; D006801:Humans; D019957:Motor Skills Disorders / Q000503:physiopathology / Q000534:rehabilitation; D010291:Paresis / Q000209:etiology / Q000503:physiopathology* / Q000534:rehabilitation; D016032:Randomized Controlled Trials as Topic; D020521:Stroke / Q000150:complications* / Q000503:physiopathology / Q000628:therapy*; D000071939:Stroke Rehabilitation