title: Mental Fatigue: Impairment of Technical Performance in Small-Sided Soccer Games.
abstract: OBJECTIVE
  To assess the effects of mental fatigue on physical and technical performance in small-sided soccer games.
  
  
  METHODS
  Twenty soccer players (age 17.8 ± 1.0 y, height 179 ± 5 cm, body mass 72.4 ± 6.8 kg, playing experience 8.3 ± 1.4 y) from an Australian National Premier League soccer club volunteered to participate in this randomized crossover investigation. Participants played 15-min 5-vs-5 small-sided games (SSGs) without goalkeepers on 2 occasions separated by 1 wk. Before the SSG, 1 team watched a 30-min emotionally neutral documentary (control), while the other performed 30 min of a computer-based Stroop task (mental fatigue). Subjective ratings of mental and physical fatigue were recorded before and after treatment and after the SSG. Motivation was assessed before treatment and SSG; mental effort was assessed after treatment and SSG. Player activity profiles and heart rate (HR) were measured throughout the SSG, whereas ratings of perceived exertion (RPEs) were recorded before the SSG and immediately after each half. Video recordings of the SSG allowed for notational analysis of technical variables.
  
  
  RESULTS
  Subjective ratings of mental fatigue and effort were higher after the Stroop task, whereas motivation for the upcoming SSG was similar between conditions. HR during the SSG was possibly higher in the control condition, whereas RPE was likely higher in the mental-fatigue condition. Mental fatigue had an unclear effect on most physical-performance variables but impaired most technical-performance variables.
  
  
  CONCLUSIONS
  Mental fatigue impairs technical but not physical performance in small-sided soccer games.
authors.forename: Oliver O
authors.initials: OO
authors.lastname: Badin
authors.forename: Mitchell R
authors.initials: MR
authors.lastname: Smith
authors.forename: Daniele
authors.initials: D
authors.lastname: Conte
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Coutts
mesh_terms: D000293:Adolescent; D000339:Affect; D054874:Athletic Performance / Q000523:psychology*; D003071:Cognition; D003163:Competitive Behavior; D018592:Cross-Over Studies; D040362:Geographic Information Systems; D006126:Group Processes; D006801:Humans; D008297:Male; D005222:Mental Fatigue / Q000209:etiology* / Q000523:psychology; D009119:Muscle Contraction; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000502:physiology*; D010807:Physical Endurance; D012916:Soccer / Q000523:psychology*; D057190:Stroop Test; D013647:Task Performance and Analysis; D013997:Time Factors; D014741:Video Recording
keywords: cognitive fatigue; football; perception of effort; team sport