Among risk factors for stress fractures in athletes, which factor is associated with osteopenia and increased fracture risk, particularly in female athletes?

• A. Adequate calcium intake
• B. Amenorrhea in female athletes
• C. Non-weight-bearing exercises
• D. Balanced footwear with good shock absorption

Answer: (B)

Estrogen helps maintain bone density by limiting bone resorption. In female athletes, amenorrhea often signals low energy availability that lowers estrogen production. This hypoestrogenic state accelerates bone loss, lowering bone mineral density into osteopenia and increasing the risk of stress fractures under repetitive stress. While good calcium intake supports bone health and proper footwear or non-weight-bearing activity can influence injury risk in other ways, amenorrhea directly captures the hormonal state that weakens bone and raises fracture risk.