title: Skeletal muscle functional and structural adaptations after eccentric overload flywheel resistance training: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The purpose of this meta-analysis was to examine the effect of flywheel (FW) resistance training with Eccentric Overload (FW-EOT) on muscle size and functional capacities (i.e. strength and power) in athletes and healthy subjects, and to compare FW-induced adaptations with those triggered by traditional resistance exercise interventions.
  
  
  METHODS
  A systematic review and meta-analysis of randomised controlled trials.
  
  
  METHODS
  A search of electronic databases [PubMed, MEDLINE (SportDiscus), Web of Science, Scopus and PEDro] was conducted to identify all publications employing FW-EOT up to April 30, 2016. Outcomes were analyzed as continuous outcomes using a random effects model to calculate a standardized mean difference (SMD) and 95% CI. A total of 9 studies with 276 subjects and 92 effect sizes met the inclusion criteria and were included in the statistical analyses.
  
  
  RESULTS
  The overall pooled estimate from the main effects analysis was 0.63 (95% CI 0.49-0.76) with a significant (p<0.001) Z overall effect of 9.17. No significant heterogeneity (p value=0.78) was found. The meta-analysis showed significant differences between FW-EOT vs. conventional resistance training in concentric and eccentric strength, muscle power, muscle hypertrophy, vertical jump height and running speed, favoring FW-EOT.
  
  
  CONCLUSIONS
  This meta-analysis provides evidence supporting the superiority of FW-EOT, compared with traditional weight-stack exercise, to promote skeletal muscle adaptations in terms of strength, power and size in healthy subjects and athletes.
authors.affiliation: Institute of Biomedicine (IBIOMED), University of León, Spain. Electronic address: smaroi@unileon.es.
authors.forename: Sergio
authors.initials: S
authors.lastname: Maroto-Izquierdo
authors.affiliation: Department of Health Sciences, European University Miguel de Cervantes, Spain.
authors.forename: David
authors.initials: D
authors.lastname: García-López
authors.affiliation: Department of Physiology & Pharmacology, Karolinska Institutet, Sweden.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Fernandez-Gonzalo
authors.affiliation: Institute of Biomedicine (IBIOMED), University of León, Spain.
authors.forename: Osvaldo C
authors.initials: OC
authors.lastname: Moreira
authors.affiliation: Institute of Biomedicine (IBIOMED), University of León, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: González-Gallego
authors.affiliation: Institute of Biomedicine (IBIOMED), University of León, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: de Paz
mesh_terms: D000222:Adaptation, Physiological; D054874:Athletic Performance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D016032:Randomized Controlled Trials as Topic; D055070:Resistance Training / Q000379:methods*
keywords: Hypertrophy; Iso-inertial; Muscle power; Muscle strength