The purpose of this study was three-fold: (1) to describe anthropometric, maturation, and
somatotype differences of players based on playing positions; (2) to analyze variations of accumulated
load training (AcL) and fitness parameters between playing positions; and finally (3) to explain the
variation of maximal oxygen uptake (VO2max) and peak power (PP) through the AcL, body fat (BF),
maturity, somatotype and fitness levels. Twenty-seven male youth soccer players under-16 were
divided by the following positions participated in this study: six central midfielders, four wingers
(WG), five forwards, eight defenders, and four goalkeepers (GK). They were evaluated on two
occasions: pre-season and after-season. Height, sitting height, body mass, BF, girths, percentage of BF
(BF%), lean body mass, maturity, somatotype, sprint test, change of direction test, Yo-Yo intermittent
recovery test level 1, Wingate, PP, VO2max and fatigue index were assessed. Then, AcL was monitored
during training sessions. The main results revealed significant differences between player positions
for maturity offset (p = 0.001), for BF (p = 0.006), BF% (p = 0.015), and lean body mass kg (p = 0.003).
Also, there were significant differences for AcL and fatigue index in pre-season between player
positions (p < 0.05). In addition, there were some significant differences in pre- and after-season
for VO2max and PP between player positions (p < 0.05). In conclusion, GK showed higher values in
anthropometric, body composition variables and maturity offset compared to the other positions,
while WG presented lower levels of BF. In pre-season, there were more differences by player positions
for the different variables analyzed than after-season that reinforces the tactical role of the positions,
and the emphasis in increased load in the beginning of the season. This study could be used by
coaches, staff, and researchers as a reference for athletes of the same sex, age, and competitive level.Portuguese Foundation for Science and Technology, I.P., Grant/Award Number UIDP/
04748/202
