title: Higher Treadmill Training Intensity to Address Functional Aerobic Impairment after Stroke.
abstract: BACKGROUND
  Peak aerobic capacity (VO2 peak) is severely worsened after disabling stroke, having serious implications for function, metabolism, and ongoing cardiovascular risk. Work from our laboratory and others has previously shown that modest improvements in VO2 peak are possible in stroke participants with aerobic exercise training. The purpose of the current investigation was to test the extent to which greater enhancements in VO2 peak after stroke are possible using a treadmill protocol with far greater emphasis on intensity progression compared with a protocol without such emphasis.
  
  
  METHODS
  Using a randomized design, we compared stroke survivors engaged in higher intensity treadmill training (HI-TM, 80% heart rate reserve [HRR]) with those undergoing lower intensity treadmill training (LO-TM, 50% HRR). Measured outcomes were change in VO2 peak, 6-minute walk distance (6MWD), 30-ft walk times (30WT), and 48-hour step counts (48SC). LO-TM participants trained for a longer period of time per session in an effort to approximately match workload/caloric expenditure. Participants were randomized with stratification according to age and baseline walking capacity.
  
  
  RESULTS
  HI-TM participants (n = 18) had significantly greater gains in VO2 peak (+34%) than LO-TM participants (n = 16; +5%) across the 6-month intervention period (P = .001, group × time interaction). Conversely, there was no statistical difference between groups in the changes observed for 6MWD, 30WT, or 48SC.
  
  
  CONCLUSIONS
  HI-TM is far more effective than LO-TM for improving VO2 peak after disabling stroke. The magnitude of relative improvement for HI-TM was double compared with previous reports from our laboratory with probable clinical significance for this population.
authors: Department of Veterans Affairs and Veterans Affairs Medical Center, Maryland Exercise and Robotics Center of Excellence (MERCE) & Geriatric Research, Education and Clinical Center (GRECC), Baltimore, Maryland; Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland. Electronic address: fivey@grecc.umaryland.edu.
authors: Frederick M
authors: FM
authors: Ivey
authors: Department of Veterans Affairs and Veterans Affairs Medical Center, Maryland Exercise and Robotics Center of Excellence (MERCE) & Geriatric Research, Education and Clinical Center (GRECC), Baltimore, Maryland.
authors: Alyssa D
authors: AD
authors: Stookey
authors: Department of Veterans Affairs and Veterans Affairs Medical Center, Maryland Exercise and Robotics Center of Excellence (MERCE) & Geriatric Research, Education and Clinical Center (GRECC), Baltimore, Maryland; Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland.
authors: Charlene E
authors: CE
authors: Hafer-Macko
authors: Department of Veterans Affairs and Veterans Affairs Medical Center, Maryland Exercise and Robotics Center of Excellence (MERCE) & Geriatric Research, Education and Clinical Center (GRECC), Baltimore, Maryland; Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland.
authors: Alice S
authors: AS
authors: Ryan
authors: Department of Veterans Affairs and Veterans Affairs Medical Center, Maryland Exercise and Robotics Center of Excellence (MERCE) & Geriatric Research, Education and Clinical Center (GRECC), Baltimore, Maryland; Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland.
authors: Richard F
authors: RF
authors: Macko
mesh_terms: D000368:Aged; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology* / Q000534:rehabilitation*; D010101:Oxygen Consumption; D020521:Stroke / Q000150:complications*; D016138:Walking
keywords: Stroke recovery; exercise training; oxygen consumption; stroke rehabilitation