Detection of physical efficiency and performance of footballers by using GPS and K4

The aim of this Ph.D. thesis is to analyze and compare the player performance model (PPM) of footballers. The thesis tries to analyze the PPM through two different studies. The first part of the project wants to analyze the internal effort of footballers comparing the metabolic power (MP) approach of Osgnach and Di Prampero derived from the external load with use of GPS or video tracking system, with the real metabolic effort gained with a portable metabolimeter. Two different protocols were used. First protocol was performed on 20 amateur footballers from 7Th Italian League (Age: 27,3 ± 3,3, eight: 1,77 ± 3,4 and weight: 80 ± 4,5). Subjects were running 10 minutes with two different velocities 8 Km/h and at 16 Km/h (5 minutes for both) and performing a 5 minutes pause between the two. The type of running was circular asking players to maintain the velocity without performing changes of speed or direction, during the test the players were analyzed with the use of 50Hz GPS (K-Sport Universal, Italia) and a portable metabolimeter Cosmed K4 b2. The second protocol was performed on 20 semi-professional football players (Age: 26,3 ± 3,6, eight: 1,78 ± 4,5 and weight 77 ± 4,3) from a football team of 4Th Italian Championship league. Change the sample was important in order to investigate the possible differences that can be recorded between amateur and semi-professional athletes. The test protocol it was composed in 6 parts (18 minutes) including 2 recovery periods, one at the beginning of the test in order to evaluate the individual basal metabolism and one at the end of the test to determinate the recovery time. The second part of the Ph.D. project was to analyze the PPM of Armenian Premier League during matches using 25 GPS 10 Hz (K-Sport, Montelabbate, Italy), in order to compare data obtained with literature from major European championship. In total were analyzed 25 matches (10 wins, 10 Loses and 5 draws), 33 different players (age 24,3 ± 4,2, eight 1,76 ± 4,2 and weight 74 ± 3,5) and in 270 performances (10,8 for matches).