By Emily Stout, B.S.

Female teenage athletes who over-train or under-eat may be at risk of an early form of a debilitating condition usually associated with postmenopausal women — the bone-thinning disease, osteoporosis.

Peak bone mass is gained between the ages of 20 and 30, which serves as a bone bank for the remainder of life. Physical activity is an essential factor in bone health and maintaining bone mass, but can put athletes at risk if done in excess or to the point where there is a decline in the production of estrogen, a hormone implicated in healthy bones. Other individuals at high risk include anorexics, whose low calorie intake weakens bones, and asthmatics treated with steroids, a class of drugs that can interfere with the production of a key bone matrix protein. Striving for healthy bones in the teenage years is important because once bone density is lost, it is difficult if not impossible to restore.

To ensure healthy bones in teenage female athletes:

• Exercise: Exercise strengthens bones, but it is important to differentiate between non-weight bearing activities such as swimming that benefit cardiovascular health, and weight-bearing exercise that maximizes bone acquisition. Running, jumping and gymnastics are weight-bearing activities that help to optimize bone health.

• Adequate Energy and Calcium Intake: For teenagers, “deposits” in the bone bank can be made by consuming a calcium quota of 1200 to 1500 mg per day, the equivalent of four to five glasses of milk. Calcium is a key to optimal bone health, but other nutrients such as protein, vitamin D, magnesium, vitamin K and others also play a role in healthy bones. Therefore, it is important that women have an overall healthy diet, including a variety of foods and adequate calories.

• Regular Menstruation: For female athletes with sub-optimal estrogen production, hormone therapy with estrogen and progesterone, or oral contraceptives may also be beneficial along with an adequate daily intake of calcium. A decreased intensity of training may be necessary until regular menstruation resumes.

For additional information please contact NIFS at 317.274.3432 or visit our Web site at www.nifs.org.