Intensity of real competitive soccer matches and differences among player positions

Most investigations on soccer match intensity have evaluated friendly, simulated or a small number of games on a recreational basis or including a small number of players. There are no studies investigating real competitive situations including a considerable number of athletes and games or differences among player positions using heart rate as an intensity parameter. The aim of this study was to determine Brazilian soccer game intensity (GI) during official competitive matches and to compare GI among different player positions. Heart rate (HR) was measured in 26 under-17 (U-17) and 18 under-20 (U-20) soccer players (age 16.38 plus or minus 0.5 and 18.24 plus or minus 0.66 years, respectively) during 14 and 15 official games, respectively. Individual maximal heart rate (HR sub(max)) and anaerobic threshold (AT) HR were evaluated in field tests. GI defined as %HR sub(max) was monitored considering five intensity zones ranging from 1 = < 70% HR sub(max) to 5 = 95-100% HR sub(max). Mean GI and AT intensity were 84.4 plus or minus 5.1 and 86.3 plus or minus 4.0% HR sub(max) for the U-17 category and 84.1 plus or minus 4.1 and 87.0 plus or minus 5.1% HR sub(max) for the U-20 category, respectively. Wingbacks (WB) spent more time in zone 5 than forwards (FW) (p