The Female Athlete Triad: a warning to women runners.

Losing your menstrual period is not something you should ignore. It could be a sign that your body is under too much stress. Work with your doctor to maintain a healthy balance between competitive edge and health.

Although busty voluptuous-looking women have taken a prominent role in American culture as seen in magazines, movies, TV, and even ads for health clubs, the image of the wafer-thin, nearly emaciated Ally McBeal-type is still a powerful force in our society. Competitive female runners may fall into that category by virtue of their training and a reluctance to carry any extra weight. The damage that can be done to a woman's health, especially wreaking havoc on the endocrine system--the system that controls the release of many important hormones--can be serious.

The Female Athlete Triad refers to a combination of disrupted eating habits, menstrual irregularities, and osteoporosis. These three components are interrelated with the combination of intense exercise, low calorie intake, and low body fat percentage leading to a loss of menstrual periods and ultimately osteoporosis or bone thinning. Only recently are scientists recognizing the potential for permanent consequences.

Among those at the very highest risk for the Female Athlete Triad are endurance runners. There is a direct relationship between the number of miles run per week and the loss of menstrual periods (amenorrhea). One study showed amenorrhea among nearly half of all women who run more than 70 miles a week. With more and more women of every age running marathons and ultra distance events, every female runner should be armed with the knowledge necessary to recognize symptoms of the problem and understand the consequences.

The Triad usually begins when you consume fewer calories than your body needs to carry on business. Even a well-rounded diet is a problem if energy demands are greater than calories consumed. Sometimes female runners end up inadvertently with an energy deficit, but sometimes it happens in a deliberate effort to lose weight, especially body fat, in an attempt to improve running times. In response, the ovaries cut down production of estrogen. As estrogen production is reduced, menstrual periods become fewer and less regular, and eventually can stop altogether. With poor diet and low calcium intake, and estrogen levels that mimic menopause, osteoporosis (loss of normal bone density) results along with a serious increase in fracture risk, especially for the runner.

If you are a female runner anywhere between puberty and menopause, and your periods become irregular or stop, it is not a benign condition. Once other causes are ruled out, process of elimination leaves you with the diagnosis of an exercise-induced amenorrhea. Not only are you at increased risk of bone fracture while experiencing a loss of periods, the condition may not be reversible. Once the damage is done, the risk of fracture may be higher at all subsequent stages whether or not diet is improved, exercise intensity is reduced, and periods resume.

All athletes need to provide themselves an energy-rich diet adequate for the demands of running and training. A healthy diet may be the only means necessary to prevent The Female Athlete Triad at almost any level of training intensity. Provide the body with enough energy to compensate for the caloric demands of running, and the endocrine system will run smoothly. Improving diet may not just help reduce risk of osteoporosis, but can also improve performance and delay the onset of fatigue.

Treatment of exercise-induced amenorrhea requires increasing caloric intake, including adequate calcium and Vitamin D to help guard against osteoporosis, reducing training intensity, increasing body fat percentage, and possible hormone replacement therapy. Something as simple as taking birth control pills can be an effective way to replace lost estrogen, but it is only a stop-gap solution. A study at Arizona State University treated four amenorrheic athletes by giving them one can a day of GatorPro (a 360 calorie sports supplement drink) and adding one day of rest per week. All gained weight and body fat, and three resumed their periods during or soon after the 20-week program.

By far, the best way to deal with this problem is to avoid it in the first place. Training intensely and wisely can produce a competitive athlete, healthy for life. If you notice a change in your periods, see your doctor and correct the problem before you end up with bones too fragile to carry you through the miles.

(International Journal of Sport Nutrition, 1999, Vol. 9, pp. 70-88)