Assessment of physical performance using GPS during competitive matches in youth elite soccer players

The aim of this study was to measure physical performance during official soccer competitions using Global Positioning System (GPS) technology. Sixteen youth professional soccer players (age 18±0.2 years, weight 70±7 kg, height 179±6 cm) from an Italian SerieA club were monitored over seven official matches with GPS (SPI-Pro X, GPSports). The high and very-high speed running distances (HSR, 14.4-19.7 and VHSR, >19.8 km/h, respectively) as well as the high metabolic power distance (HPR, >20 W/kg) and the mean metabolic power (Pmet) were considered as indicators of physical performance. No time x position interactions were found (all P>0.05). A significant decrease in HSR, HPR and Pmet occurred through the game (all P<0.001). HSR was 33% lower in the last than in the first 15 min of the game (21.4 vs. 32.2 m/min, P=0.006), whereas HPR and Pmet were lower in the last four compared with the first two 15-min periods (all P<0.05). Full-backs performed significantly higher VHSR (9.4 vs. 5.3 m/min, P=0.03) and Pmet (14.5 vs. 12.1 W/kg, P=0.046) and tended to have higher HPR (29.8 vs 21.1 m/min, P=0.054) compared with central defenders. No significant differences were observed between the other playing positions. This is the first study to assess physical performance during official soccer match-play using GPS technology. The results show that high speed and power distances decreased throughout the game and were higher in full-backs compared with central defenders. Thus, GPS and its-related metabolic power measurements can be used as an additional tool to evaluate match physical performance.