London: Using GPS technology to track football players' speed and acceleration, researchers have discovered that excessive workload put the players at greatest injury risk. "Our research has huge practical and scientific application. It expands on a recent body of literature in rugby league and cricket which has proposed that the prescription of workloads may be more indicative of injury than the load itself,” said lead researcher Laura Bowen from Southampton Football Club in Britain. "The results of our study demonstrate this, with high, excessive workloads associated with the greatest injury risk. However, when the players were exposed to these high loads progressively, over a period of time, the risk of injury reduced significantly,” she noted. The study used a range of player performance data gathered by GPS equipment worn by the players in training, including total distance covered, distance covered at high speed, total load/forces experienced and short bursts of speed. This data was then analysed in relation to 'recordable injuries', which caused an absence from football activity -- classified as mild, moderate or severe -- of anything from a couple of days to several weeks. The findings, published in the British Journal of Sports Medicine, showed that high level of acceleration over a three-week training period was the strongest indicator of overall and non-contact injury risk. "To increase the chances of success, coaches give players training loads which push the boundaries of what footballers can achieve without exceeding what their bodies can tolerate,” corresponding author François-Xavier Li from the University of Birmingham said. "An appropriate balance is required between training, competition and recovery to hit peak performance, whilst avoiding injury. However, this balance is not always adequately maintained -- highlighted by the higher injury rate in football than many other team sports,” Li noted.