title: Agility in Team Sports: Testing, Training and Factors Affecting Performance.
abstract: BACKGROUND
  Agility is an important characteristic of team sports athletes. There is a growing interest in the factors that influence agility performance as well as appropriate testing protocols and training strategies to assess and improve this quality.
  
  
  OBJECTIVE
  The objective of this systematic review was to (1) evaluate the reliability and validity of agility tests in team sports, (2) detail factors that may influence agility performance, and (3) identify the effects of different interventions on agility performance.
  
  
  METHODS
  The review was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We conducted a search of PubMed, Google Scholar, Science Direct, and SPORTDiscus databases. We assessed the methodological quality of intervention studies using a customized checklist of assessment criteria.
  
  
  RESULTS
  Intraclass correlation coefficient values were 0.80-0.91, 0.10-0.81, and 0.81-0.99 for test time using light, video, and human stimuli. A low-level reliability was reported for youth athletes using the video stimulus (0.10-0.30). Higher-level participants were shown to be, on average, 7.5% faster than their lower level counterparts. Reaction time and accuracy, foot placement, and in-line lunge movement have been shown to be related to agility performance. The contribution of strength remains unclear. Efficacy of interventions on agility performance ranged from 1% (vibration training) to 7.5% (small-sided games training).
  
  
  CONCLUSIONS
  Agility tests generally offer good reliability, although this may be compromised in younger participants responding to various scenarios. A human and/or video stimulus seems the most appropriate method to discriminate between standard of playing ability. Decision-making and perceptual factors are often propositioned as discriminant factors; however, the underlying mechanisms are relatively unknown. Research has focused predominantly on the physical element of agility. Small-sided games and video training may offer effective methods of improving agility, although practical issues may hinder the latter.
authors.affiliation: Aspetar-Qatar Orthopaedic and Sports Medicine Hospital, National Sports Medicine Programme, Excellence in Football Project, PO BOX 29222, Doha, Qatar. darren.paul@aspetar.com.
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Paul
authors.affiliation: School of Exercise Science, Australian Catholic University, Brisbane, QLD, Australia.
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Gabbett
authors.affiliation: Aspetar-Qatar Orthopaedic and Sports Medicine Hospital, National Sports Medicine Programme, Excellence in Football Project, PO BOX 29222, Doha, Qatar.
authors.forename: George P
authors.initials: GP
authors.lastname: Nassis
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D009048:Motor Skills; D009068:Movement; D064797:Physical Conditioning, Human / Q000502:physiology; D011930:Reaction Time; D015203:Reproducibility of Results; D013177:Sports