The Association Between Noncontact Injuries and the Acute-Chronic Workload Ratio in Elite-Level Athletes: A Critically Appraised Topic.

Clinical Scenario: Workload monitoring and management of an athlete is viewed by many as an essential training component to determine if an athlete is adapting to a training program and to minimize injury risk. Although training workload may be measured a variety of different ways, session rate of perceived exertion (sRPE) is often used in the literature due to its clinical ease. In recent years, sports scientists have been investigating sRPE as a measure of internal workload and its relationship to injury in elite-level athletes using a metric known as the acute:chronic workload ratio (ACWR). This critically appraised topic was conducted to determine if internal workload using the ACWR is associated with injury. Focused Clinical Question: In elite-level athletes, is there an association between the ACWR for sRPE and noncontact injuries? Summary of Search, Best Evidence Appraised, and Key Findings: The literature was searched for studies investigating the association between noncontact injuries and the sRPE ACWR in elite athletes. Three prospective cohort studies were included. Two studies found that high ACWR led to 2.0 to 4.5 times greater injury risk compared with a more balanced ACWR. One study found that low chronic workloads coupled with a low ACWR were associated with injury. Clinical Bottom Line: The majority of evidence suggests that when the acute workload exceeds the chronic workload, there is an increase in injury risk. The evidence also supports that a low chronic workload with a low ACWR should be considered as an injury risk factor. Strength of Recommendation: Based on the American Family Physician's Strength of Recommendation Taxonomy, there is level A evidence to support the sRPE ACWR as a risk factor for noncontract injuries in elite athletes.