title: Group-based exercise combined with dual-task training improves gait but not vascular health in active older adults without dementia.
abstract: BACKGROUND
  Gait abnormalities and vascular disease risk factors are associated with cognitive impairment in aging.
  
  
  OBJECTIVE
  To determine the impact of group-based exercise and dual-task training on gait and vascular health, in active community-dwelling older adults without dementia.
  
  
  METHODS
  Participants [n=44, mean (SD) age: 73.5 (7.2) years, 68% female] were randomized to either intervention (exercise+dual-task; EDT) or control (exercise only; EO). Each week, for 26 weeks, both groups accumulated 50 or 75 min of aerobic exercise from group-based classes and 45 min of beginner-level square stepping exercise (SSE). Participants accumulating only 50 min of aerobic exercise were instructed to participate in an additional 25 min each week outside of class. The EDT group also answered cognitively challenging questions while performing SSE (i.e., dual-task training). The effect of the interventions on gait and vascular health was compared between groups using linear mixed effects models.
  
  
  RESULTS
  At 26 weeks, the EDT group demonstrated increased dual-task (DT) gait velocity [difference between groups in mean change from baseline (95% CI): 0.29 m/s (0.16-0.43), p<0.001], DT step length [5.72 cm (2.19-9.24), p =0.002], and carotid intima-media thickness [0.10mm (0.003-0.20), p=0.04], as well as reduced DT stride time variability [8.31 coefficient of variation percentage points (-12.92 to -3.70), p<0.001], when compared to the EO group.
  
  
  CONCLUSIONS
  Group-based exercise combined with dual-task training can improve DT gait characteristics in active older adults without dementia.
authors.affiliation: Health & Rehabilitation Sciences, Faculty of Health Sciences, Western University, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada. Electronic address: mgregor7@uwo.ca.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Gregory
authors.affiliation: Health & Rehabilitation Sciences, Faculty of Health Sciences, Western University, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada; Department of Family Medicine, Schulich School of Medicine & Dentistry, Western University, ON, Canada; Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA. Electronic address: dawn.gill@uwo.ca.
authors.forename: Dawn P
authors.initials: DP
authors.lastname: Gill
authors.affiliation: Department of Epidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Robarts Clinical Trials, Robarts Research Institute, Western University, London, ON, Canada. Electronic address: gzou@robarts.ca.
authors.forename: Guangyong
authors.initials: G
authors.lastname: Zou
authors.affiliation: Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, Vancouver, BC, Canada. Electronic address: teresa.ambrose@ubc.ca.
authors.forename: Teresa
authors.initials: T
authors.lastname: Liu-Ambrose
authors.affiliation: Faculty of Education, Mie University, Japan. Electronic address: rshige@edu.mie-u.ac.jp.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Shigematsu
authors.affiliation: Canadian Centre for Activity and Aging, Faculty of Health Sciences, Western University, London, ON, Canada. Electronic address: cfitzge4@uwo.ca.
authors.forename: Clara
authors.initials: C
authors.lastname: Fitzgerald
authors.affiliation: Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada. Electronic address: vladimir.hachinski@lhsc.on.ca.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Hachinski
authors.affiliation: Department of Kinesiology, Faculty of Health Sciences, Western University, London, ON, Canada. Electronic address: kshoemak@uwo.ca.
authors.forename: Kevin
authors.initials: K
authors.lastname: Shoemaker
authors.affiliation: Health & Rehabilitation Sciences, Faculty of Health Sciences, Western University, London, ON, Canada; Lawson Health Research Institute, London, ON, Canada; Department of Family Medicine, Schulich School of Medicine & Dentistry, Western University, ON, Canada; Canadian Centre for Activity and Aging, Faculty of Health Sciences, Western University, London, ON, Canada; Department of Kinesiology, Faculty of Health Sciences, Western University, London, ON, Canada. Electronic address: petrella@uwo.ca.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Petrella
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059168:Carotid Intima-Media Thickness; D015444:Exercise / Q000523:psychology; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005684:Gait / Q000502:physiology*; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D009048:Motor Skills; D026741:Physical Therapy Modalities; D004856:Postural Balance / Q000502:physiology*; D012111:Residence Characteristics; D013647:Task Performance and Analysis; D016896:Treatment Outcome
keywords: Dual-task training; Exercise; Gait; Group-based programs; Randomized controlled trial; Vascular health