Bone Stress Injury Recovery and Return to Sport: A Natural History Study

Inclusion Criteria: * Diagnosed BSI of the tibia, metatarsal two, three, or four, femoral neck or femoral shaft by MRI, grade two or higher on the Fredericson grading scale7 * Age 16-35 years * Body Mass Index 17.5-30 kg/m2 * Self-reported minimum of three hours per week of endurance exercise that includes running at least fifteen miles per week during three months prior to injury * Study enrollment within three weeks of MRI Exclusion Criteria: * Self-reported history of endocrine disorder that impacts bone health (e.g., diabetes, hyperthyroidism, or primary hyperparathyroidism) * Self-reported history of bone disease or other bone disorder (e.g., osteopetrosis, osteogenesis imperfecta, osteomalacia, rickets, Paget's disease, or multiple myeloma) * Use of thyroid hormone replacement at suppressive doses for a history of thyroid cancer * History of chemotherapy or radiation treatment for cancer in the past 5 years * Currently taking or have taken oral glucocorticoids for greater than three months (e.g., prednisone or hydrocortisone) * Current or prior use of osteoporosis medications (e.g., bisphosphonates, teriparatide) * Current use of anti-seizure medications (e.g. Phenytoin (Dilantin), Carbamazepine (Tegretol), Phenobarbitol) * Currently pregnant * Currently lactating * Contraindications to MRI * BSI is planned to be managed operatively * Tibial BSI on the anterior aspect of the bone * Participants that are non-English speaking