title: High-speed resistance training is more effective than low-speed resistance training to increase functional capacity and muscle performance in older women.
abstract: OBJECTIVE
  To examine the effects of 12 weeks of high-speed resistance training (RT) versus low-speed RT on muscle strength [one repetition of maximum leg-press (1RMLP) and bench-press (1RMBP), plus dominant (HGd) and non-dominant maximum isometric handgrip], power [counter-movement jump (CMJ), ball throwing (BT) and 10-m walking sprint (S10)], functional performance [8-foot up-and-go test (UG) and sit-to-stand test (STS)], and perceived quality of life in older women.
  
  
  METHODS
  45 older women were divided into a high-speed RT group [EG, n=15, age=66.3±3.7y], a low-speed RT group [SG, n=15, age=68.7±6.4y] and a control group [CG, n=15, age=66.7±4.9y]. The SG and EG were submitted to a similar 12-week RT program [3 sets of 8 reps at 40-75% of the one-repetition maximum (1<RM), CMJ and BT] using slow, controlled (3s) concentric muscle actions for the SG and using fast, explosive (<1s) concentric muscle actions for the EG (20% less work per exercise without CMJ and BT).
  
  
  RESULTS
  Over the 12-week training period, both RT groups showed small to large clinically significant improvements in the dependent variables; however, a significant difference was found between the EG and SG for the performance changes in BT, S10 and UG (20% vs. 11%, p<0.05; 14% vs. 9%, p<0.05; 18% vs. 10%, p<0.01; respectively). No significant changes were observed for the CG.
  
  
  CONCLUSIONS
  Both RT interventions are effective in improving functional capacity, muscle performance and quality of life in older women, although a high-speed RT program induces greater improvements in muscle power and functional capacity.
authors.affiliation: Department of Physical Activity Sciences, Universidad de Los Lagos, Osorno, Chile.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Ramírez-Campillo
authors.affiliation: Department of Physical Activity Sciences, Universidad de Los Lagos, Osorno, Chile.
authors.forename: Angélica
authors.initials: A
authors.lastname: Castillo
authors.affiliation: School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Carlos I
authors.initials: CI
authors.lastname: de la Fuente
authors.affiliation: School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: Christian
authors.initials: C
authors.lastname: Campos-Jara
authors.affiliation: Laboratory of Exercise Sciences, MEDS Clinic, Santiago, Chile.
authors.forename: David C
authors.initials: DC
authors.lastname: Andrade
authors.affiliation: Family Health Center, Los Lagos, Chile.
authors.forename: Cristian
authors.initials: C
authors.lastname: Álvarez
authors.affiliation: Department of Physical Education, Sport and Recreation, Universidad de La Frontera, Temuco, Chile.
authors.forename: Cristian
authors.initials: C
authors.lastname: Martínez
authors.affiliation: School of Health, Duoc UC, Santiago, Chile.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Castro-Sepúlveda
authors.affiliation: Department of Sport Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Research Centre in Sports, Health and Human Development, Vila Real, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Pereira
authors.affiliation: Research Centre in Sports, Health and Human Development, Vila Real, Portugal; Department of Sport Sciences, University of Beira Interior, Covilhã, Portugal.
authors.forename: Mário C
authors.initials: MC
authors.lastname: Marques
authors.affiliation: Department of Health Sciences, Public University of Navarre, Navarre, Spain. Electronic address: mikel.izquierdo@gmail.com.
authors.forename: Mikel
authors.initials: M
authors.lastname: Izquierdo
mesh_terms: D000222:Adaptation, Physiological; D000367:Age Factors; D000368:Aged; D000375:Aging; D005260:Female; D018737:Hand Strength; D006304:Health Status; D006801:Humans; D007537:Isometric Contraction; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D011788:Quality of Life; D055070:Resistance Training / Q000379:methods*; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome; D016138:Walking
keywords: Adaptation; Aging; Power output; Resistance training; Women