title: Resistance training and executive functions: a 12-month randomized controlled trial.
abstract: BACKGROUND
  Cognitive decline among seniors is a pressing health care issue. Specific exercise training may combat cognitive decline. We compared the effect of once-weekly and twice-weekly resistance training with that of twice-weekly balance and tone exercise training on the performance of executive cognitive functions in senior women.
  
  
  METHODS
  In this single-blinded randomized trial, 155 community-dwelling women aged 65 to 75 years living in Vancouver were randomly allocated to once-weekly (n = 54) or twice-weekly (n = 52) resistance training or twice-weekly balance and tone training (control group) (n = 49). The primary outcome measure was performance on the Stroop test, an executive cognitive test of selective attention and conflict resolution. Secondary outcomes of executive cognitive functions included set shifting as measured by the Trail Making Tests (parts A and B) and working memory as assessed by verbal digit span forward and backward tests. Gait speed, muscular function, and whole-brain volume were also secondary outcome measures.
  
  
  RESULTS
  Both resistance training groups significantly improved their performance on the Stroop test compared with those in the balance and tone group (P < or = .03). Task performance improved by 12.6% and 10.9% in the once-weekly and twice-weekly resistance training groups, respectively; it deteriorated by 0.5% in the balance and tone group. Enhanced selective attention and conflict resolution was significantly associated with increased gait speed. Both resistance training groups demonstrated reductions in whole-brain volume compared with the balance and tone group at the end of the study (P < or = .03).
  
  
  CONCLUSIONS
  Twelve months of once-weekly or twice-weekly resistance training benefited the executive cognitive function of selective attention and conflict resolution among senior women.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00426881.
authors.affiliation: BrainResearch Centre, Centre for Hip Health and Mobility, Vancouver Coastal Research Institute, Department of Physical Therapy, University of British Columbia. 357-2647 Willow St, Vancouver, BC V5Z 3P1, Canada. tlambrose@exchange.ubc.ca
authors.forename: Teresa
authors.initials: T
authors.lastname: Liu-Ambrose
authors.forename: Lindsay S
authors.initials: LS
authors.lastname: Nagamatsu
authors.forename: Peter
authors.initials: P
authors.lastname: Graf
authors.forename: B Lynn
authors.initials: BL
authors.lastname: Beattie
authors.forename: Maureen C
authors.initials: MC
authors.lastname: Ashe
authors.forename: Todd C
authors.initials: TC
authors.lastname: Handy
mesh_terms: D000368:Aged; D003071:Cognition; D056344:Executive Function; D015444:Exercise; D005260:Female; D005684:Gait; D006801:Humans; D008568:Memory; D053580:Muscle Strength; D055070:Resistance Training; D016037:Single-Blind Method; D014145:Trail Making Test