Adherence as the key to anterior cruciate ligament injury prevention programme success: From efficacy to effectiveness

High-quality anterior cruciate ligament (ACL) injury prevention programmes such as the FIFA 11+ and PEP warm-up have demonstrated strong efficacy in controlled trials, yet their real-world impact remains limited. The primary reason is not the design of these neuromuscular training protocols, but inadequate adherence by athletes and teams. Evidence consistently shows that only individuals with high adherence, typically ≥75% of prescribed sessions, achieve meaningful ACL injury risk reduction, whereas moderate or low adherence provides little benefit. In everyday sports settings, athletes struggle to follow prevention programmes due to time constraints, limited supervision, low motivation, and competing training priorities. These barriers result in poor fidelity, inconsistent use, and incomplete implementation across youth, amateur, and even elite sport. Understanding adherence as a multidimensional construct encompassing frequency, technique quality, and supervision is essential for bridging the gap between programme efficacy and real-world effectiveness. Enhancing coach buy-in, integrating exercises into regular practice, improving supervision, and leveraging digital tools may substantially increase adherence and translate proven protocols into meaningful injury prevention outcomes. Ultimately, closing the adherence gap is more important than discovering new exercises; changing athlete and coach behaviour is the key to achieving consistent, large-scale reductions in ACL injuries.