Relative Energy Deficiency in Sport (RED-S) and Bone Stress Injuries

Relative Energy Deficiency in Sport (RED-S) is a syndrome caused by low energy availability that has significant physiological consequences. Bone stress injuries (BSIs), including stress fractures, are overuse injuries that occur when there is an imbalance of bone microdamage and its removal and replacement via bone remodeling. Female athletes are at particular risk of RED-S, which can manifest as bone stress injury, as well as associated pathologies including disordered eating and oligomenorrhea/amenorrhea. Female athletes should be screened for risk factors for RED-S so that it can be identified and treated early. BSIs can be diagnosed by patient history and physical examination, with imaging used for confirmation. Management of BSIs differ according to their location, with high-risk injuries requiring a highly nuanced treatment approach in the context of shared decision-making. These athletes should also be concurrently evaluated for low energy availability, which if identified may require addressing disordered eating, hormone deficiency, and inadequate nutrition with an interdisciplinary team. Return to sport decisions should be individualized while informed by published guidelines.