title: Physical Demands of Top-Class Soccer Friendly Matches in Relation to a Playing Position Using Global Positioning System Technology.
abstract: The aim of this study was to examine the physical demands imposed on professional soccer players during 11-a-side friendly matches in relation to their playing position, using global positioning system (GPS) technology. One hundred and eleven match performances of a Spanish "La Liga" team during the 2010-11 and 2011-12 pre-seasons were selected for analysis. The activities of the players were monitored using GPS technology with a sampling frequency of 1 Hz. Total distance covered, distance in different speed categories, accelerations, and heart rate responses were analyzed in relation to five different playing positions: central defenders (n=23), full-backs (n=20), central midfielders (n=22), wide midfielders (n=26), and forwards (n=20). Distance covered during a match averaged 10.8 km, with wide and central midfielders covering the greatest total distance. Specifically, wide midfielders covered the greatest distances by very high-intensity running (>19.8 km·h-1) and central midfielders by jogging and running (7.2-19.7 km·h-1). On the other hand, central defenders covered the least total distance and at high intensity, although carried out more (p<0.05-0.01) accelerations than forwards, wide midfielders, and fullbacks. The work rate profile of the players obtained with the GPS was very similar to that obtained with semi-automatic image technologies. However, when comparing results from this study with data available in the literature, important differences were detected in the amount of distance covered by sprinting, which suggests that caution should be taken when comparing data obtained with the GPS with other motion analysis systems, especially regarding high-intensity activities.
authors.affiliation: Sports Department, Physical Activity and Sport Sciences Faculty, Technical University of Madrid.
authors.forename: Javier
authors.initials: J
authors.lastname: Mallo
authors.affiliation: University of Castilla la Mancha.
authors.forename: Esteban
authors.initials: E
authors.lastname: Mena
authors.affiliation: Autónoma University of Madrid.
authors.forename: Fabio
authors.initials: F
authors.lastname: Nevado
authors.affiliation: Camilo José Cela University of Madrid. Rayo Vallecano de Madrid.
authors.forename: Víctor
authors.initials: V
authors.lastname: Paredes
keywords: Association football; GPS; accelerations; heart rate; high-intensity activities