Conclusions Our results demonstrate that the existence of a relationship between training load and injury continues to be well supported in the literature and is strongest for subjective internal training load .
The directionality of this relationship appears to depend on the type and timeframe of load measured
Background The relationship between training load and musculoskeletal injury is a rapidly advancing area of research in need of an up date d systematic review .
Previous injury as a risk factor for injury in elite football: a prospective study over two consecutive seasons
Background : Previous injury is often proposed to be a risk factor for football injury , but most studies rely on players reporting their own medical history and are thus potentially subject to recall bias . Little is known about the natural variation in injury pattern between seasons . Objectives : To study whether prospect ively recorded injuries during one season are associated with injuries sustained during the following season , and to compare injury risk and injury pattern between consecutive seasons . Methods : The medical staffs of 12 elite Swedish male football teams prospect ively recorded  individual exposure and time loss injuries over two full consecutive seasons ( 2001 and 2002 ) . A multivariate model was used to determine the relation between previous injury , anthropometric data , and the risk of injury . Results : The training and match injury incidences were similar between seasons ( 5.1 v 5.3 injuries/1000 training hours and 25.9 v 22.7/1000 match hours ) , but analysis of injury severity and injury patterns showed variations between seasons . Players who were injured in the 2001 season were at greater risk of any injury in the following season compared with non-injured players ( hazard ratio 2.7 ; 95 % confidence interval 1.7 to 4.3 , p<0.0001 ) . Players with a previous hamstring injury , groin injury , and knee joint trauma were two to three times more likely to suffer an identical injury in the following season , whereas no such relation was found for ankle sprain . Age was not associated with an increased injury risk . Conclusions : This study confirmed previous results showing that previous injury is an important risk factor for football injury . Overall injury incidences were similar between consecutive seasons , indicating that an injury surveillance study covering one full season can provide a reasonable overview of the injury problem among elite football players in a specific environment . However , a prolonged study period is recommended for analyses of specific injury patterns
Conclusions Our results demonstrate that the existence of a relationship between training load and injury continues to be well supported in the literature and is strongest for subjective internal training load .
The directionality of this relationship appears to depend on the type and timeframe of load measured
Background The relationship between training load and musculoskeletal injury is a rapidly advancing area of research in need of an up date d systematic review .