In football, high-intensity running (distance covered during high-velocity movements) has been suggested to be a valid measure of physical performance.1 The ability to accelerate is a physically demanding task that can occur from a low velocity and should be considered a high-intensity action. Match analysis research excluding accelerations may underestimate the high-intensity activities performed by players. The aim of the study was to quantify the high-velocity running and acceleration efforts undertaken by elite football players and combine the two to form a high-intensity activity index (HIA). Methods Player velocity data was recorded from 13 outfield players for a total of 67 game files using a 5Hz Global Positioning System (GPSports, Australia) over the 2010-2011 A-League season. Raw velocity data was analysed using a custom-spreadsheet. Movement efforts were defined as the following: high-velocity running (HiVR) (.4.17 m/s), sprinting (.6.94 m/s), maximal acceleration (.2.78 m.s-2) and high-intensity activity (HiVR + maximal accelerations). Effort frequency and total distance were determined in addition to the commencement velocity for maximal accelerations. All data was analysed using the effect size statistic. Results & Discussion Players performed a ~6-fold greater number of maximal accelerations than sprint efforts. The number of HIA efforts was 20% greater than that of HiVR. Interestingly, 96% of maximal accelerations commenced from a velocity of .3 m/s, which under traditional movement classifications would not be considered a high-intensity effort. Conclusion The number and distance of maximal acceleration and HIA efforts exceeded that of sprint and HiVR respectively. Further, as most accelerations commenced from a low velocity, HIA will be underestimated when based purely on high-velocity movements.
© Copyright 2011 7th World Congress on Science and Football (WCSF), 2011. Alle Rechte vorbehalten.