Determining the Relationship Between Internal Load Markers and Noncontact Injuries in Young Elite Soccer Players

To examine the association and predictive ability of internal load markers with regard to noncontact injuries in young elite soccer players.

Twenty-two soccer players (18.6 [0.6] y) who competed in the Spanish U19 League participated in the study. During a full season, noncontact injuries were recorded and, using session rating of perceived exertion, internal weekly load (sum of load of all training sessions and matches for each week) and acute:chronic workload ratio (typically, acute = current week and chronic = rolling 4-wk average) were calculated. A generalized estimating equation analysis was used to examine the association of weekly and acute:chronic load-ratio markers with a noncontact injury in the subsequent week. Load variables were also analyzed for predictive ability with receiver operating characteristic curve and area under the curve.

No association was found for weekly load (odds ratio = 1.00; 90% confidence interval, 0.99-1.00) and acute:chronic load ratio (odds ratio = 0.16; 90% confidence interval, 0.01-1.84) with respect to injury occurrence. In addition, the analyzed load markers showed poor ability to predict injury occurrence (area under the curve < .50).

The results of this study suggest that internal load markers are not associated with noncontact injuries in young soccer players and present poor predictive capacity with regard to the latter.