title: Once-weekly resistance exercise improves muscle strength and neuromuscular performance in older adults.
abstract: OBJECTIVE
  To determine the effect of frequency of resistive training on gain in muscle strength and neuromuscular performance in healthy older adults.
  
  
  METHODS
  A randomized controlled trial with subjects assigned either to high-intensity resistance training 1 (EX1), 2 (EX2), or 3 (EX3) days per week for 24 weeks or to a control group (CO).
  
  
  METHODS
  An exercise facility at an academic medical center.
  
  
  METHODS
  Forty-six community-dwelling healthy men (n = 29) and women (n = 17) aged 65 to 79 years.
  
  
  METHODS
  Progressive resistance training consisting of three sets of eight exercises targeting major muscle groups of the upper and lower body, at 80% of one-repetition maximum (1-RM) for eight repetitions, either 1, 2, or 3 days per week.
  
  
  METHODS
  Dynamic muscle strength (1-RM) using isotonic equipment every 4 weeks, bone mineral density and body composition by dual energy X-ray absorptiometry (DXA), and neuromuscular performance by timed chair rise and 6-meter backward tandem walk.
  
  
  RESULTS
  For each of the eight exercises, muscle strength increased in the exercise groups relative to CO (P < .01), with no difference among EX1, EX2 and EX3 groups at any measurement interval. Percent change averaged 3.9 +/- 2.4 (CO), 37.0 +/- 15.2 (EX1), 41.9 +/- 18.2 (EX2), and 39.7 +/- 9.8 (EX3). The time to rise successfully from the chair 5 times decreased significantly (P < .01) at 24 weeks, whereas improvement in the 6-meter backward tandem walk approached significance (P = .10) in the three exercise groups compared with CO. Changes in chair rise ability were correlated to percent changes in quadriceps strength (r = -0.40, P < .01) and lean mass (r = -0.40, P < .01).
  
  
  CONCLUSIONS
  A program of once or twice weekly resistance exercise achieves muscle strength gains similar to 3 days per week training in older adults and is associated with improved neuromuscular performance. Such improvement could potentially reduce the risk of falls and fracture in older adults.
authors.affiliation: Geriatric Research, Education and Clinical Center, Veterans Affairs Medical Center, Palo Alto, California, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Taaffe
authors.forename: C
authors.initials: C
authors.lastname: Duret
authors.forename: S
authors.initials: S
authors.lastname: Wheeler
authors.forename: R
authors.initials: R
authors.lastname: Marcus
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged / Q000502:physiology*; D000704:Analysis of Variance; D001823:Body Composition; D015519:Bone Density; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D011597:Psychomotor Performance