Which of the following terms best describes a risk factor for athletic amenorrhea?

The term that best describes a risk factor for athletic amenorrhea is osteoporosis. Athletic amenorrhea often occurs in female athletes who engage in intense training or maintain low body weight, potentially leading to a decrease in estrogen levels. Estrogen plays a critical role in maintaining bone density; therefore, a deficiency can increase the risk of osteoporosis. This condition makes bones weaker and more susceptible to fractures, highlighting the link between low estrogen levels due to amenorrhea and bone health.

In this context, the other options, while they may be health concerns, do not directly correlate with the hormonal changes that lead to athletic amenorrhea or the associated risk for osteoporosis. High blood pressure, hyperthyroidism, and chronic fatigue syndrome involve different physiological processes that do not primarily influence menstrual regularity in athletes as directly as the risk posed by decreased estrogen levels and the consequent effects on bone density.