title: Physical fitness, injuries, and team performance in soccer.
abstract: OBJECTIVE
  To investigate the relationship between physical fitness and team success in soccer, and to test for differences in physical fitness between different player positions.
  
  
  METHODS
  Participants were 306 male soccer players from 17 teams in the two highest divisions in Iceland. Just before the start of the 1999 soccer season, the following variables were tested: height and weight, body composition, flexibility, leg extension power, jump height, and peak O2 uptake. Injuries and player participation in matches and training were recorded through the 4-month competitive season. Team average physical fitness was compared with team success (final league standing) using a linear regression model. Physical fitness was also compared between players in different playing positions.
  
  
  RESULTS
  A significant relationship was found between team average jump height (countermovement jump and standing jump) and team success (P = 0.009 and P = 0.012, respectively). The same trend was also found for leg extension power (P = 0.097), body composition (% body fat, P = 0.07), and the total number of injury days per team (P = 0.09). Goalkeepers demonstrated different fitness characteristics from outfield players. They were taller and heavier, more flexible in hip extension and knee flexion, and had higher leg extension power and a lower peak O2 uptake. However, only minor differences were observed between defenders, midfield players, and attackers.
  
  
  CONCLUSIONS
  Coaches and medical support teams should pay more attention to jump and power training, as well as preventive measures and adequate rehabilitation of previous injuries to increase team success.
authors.affiliation: Department of Physiology, University of Iceland, Reykjavik, Iceland.
authors.forename: Arni
authors.initials: A
authors.lastname: Arnason
authors.forename: Stefan B
authors.initials: SB
authors.lastname: Sigurdsson
authors.forename: Arni
authors.initials: A
authors.lastname: Gudmundsson
authors.forename: Ingar
authors.initials: I
authors.lastname: Holme
authors.forename: Lars
authors.initials: L
authors.lastname: Engebretsen
authors.forename: Roald
authors.initials: R
authors.lastname: Bahr
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D001265:Athletic Injuries / Q000453:epidemiology*; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D007866:Leg / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness; D012916:Soccer / Q000293:injuries* / Q000706:statistics & numerical data*; D013647:Task Performance and Analysis