CHAPTER NINETEEN Somatotype and body composition in Portuguese youth soccer players 8. Salgado, 5. Vidal, S. Silva, R. Miranda, R. Deus, R. Garganta, J. Maia, A. Rebelo and A. Seabra Faculty of Sports, University of Porto, Porto, Portugal 1. INTROD(JCTION Somatotype is an overail description of physique, a continuum from leanness and linearity to roundness and heaviness. Somatotype is expressed by a three-number rating that represents the components of endomorphy (fatness), mesomorphy (musculoskeletal development) and ectomorphy (linearity). On the other hand, body composition aims at the division of body weight into several compartments, describing components such as body fat and lean body mass in a two compartmental model. Physique and body composition play a role in lhe selection of young athletes and are associated with lhe success of youth athletes’ responses to training and competition. lt has also been suggested (Wilmore and Costill, 1999) that physical characteristics are essential items in an efficient organization of a soccer team for reaching a successfiil resolution of matches. Assessing the differences among youth soccer players who play in different positions is nol a trivial task, depending on the match, the strategy, the opponent, and lhe demands on every player which sometimes change from match to match (Gil ei aL, 2007). The aims of lhe present study were to determine somatotype components and body composition of youth Portuguese soccer players, and detect possible differences according to their playing position. 2. METHODS A sample of 187 soccer players aged 17-18 years was evaluated. The players were classified according to their playing position: goalkeepers, fulI-backs, centre-backs, midfielders and forwards (Table 1). The somatotype components were estimated using Fleath and Carter’s (1967) method based on 10 somatic measurements at various body sites. Body composition was assessed by using lhe equation of Boileau eta!. (1985). Differences by playing positions were tested with factorial analysis of variance. The Scheffé test for multiple post-hoc comparisons was used. Ali data analysis was done in SPSS 15.0.