Although many athletes do not meet strict diagnostic criteria for anorexia nervosa or bulimia nervosa, they may exhibit similar behaviors and thought patterns, placing them at a significantly increased risk for the development of the serious endocrine, metabolic, skeletal and psychiatric disorders which are often observed in these conditions.

Exercise and menstrual function. Menstruation is the cyclic discharge through the vagina of blood or tissue from the non-pregnant uterus. A normal menstrual cycle ranges from 21 to 36 days. Most women start their menstrual periods by age 16. If a woman's period has not started by that age, or her cycles are shorter than 21 days or longer than 36 days, she should consult a doctor.

Women who engage in intense training (e.g., runners who run more than 50 miles per week) may stop having their periods altogether. While the absence of a period may appear to present less of a hassle for the athlete, it is very important for a woman to find out why she is not having a cyclic menstrual period. Two to five percent of the general female population and up to 43 percent of athletic women do not have menstrual periods -- a condition known as amenorrhea. Amenorrhea, however, is not exclusive to athletes; other factors have also been found to cause amenorrhea, including pregnancy, very early menopause, anorexia nervosa and certain types of tumors.

The cause of exercise-induced amenorrhea is still not fully understood, but contributing factors include excessive weight loss/thinness, age, a previous history of menstrual abnormalities and diet -- not to mention the intensity, duration and frequency of exercise. The incidence of amenorrhea is particularly high in gymnasts, distance runners, ballet dancers and figure skaters. Amenorrhea can, however, result from intense training for any sport.

Why all the concern about amenorrhea? Research beginning in the 1980s has linked amenorrhea to low estrogen levels. Because estrogen is essential for developing and maintaining normal bone health, low levels can reflect serious deficits. Your basic skeleton -- calcium deposition in the bone -- is laid down by age 35. Theoretically, therefore, if you don't deposit adequate levels of calcium in your bones as a young woman, you may develop osteoporosis (i.e., decreased bone mass and increased susceptibility to fractures) at a relatively earlier age. Worse yet, your case of osteoporosis may be even more severe than normal. Regrettably, osteoporosis affects 25 million Americans annually.

A more common form of menstrual dysfunction is oligomenorrhea, which is infrequent menstruation of two or more months between cycles. The precise cause of menstrual irregularities is unknown. Amenorrhea and oligomenorrhea are not permanent conditions. In fact, in most highly active women, normal menstrual functioning returns one to two months after decreasing their levels of physical activity. If amenorrhea persists, a woman should undergo a thorough hormonal and gynecological evaluation and, if necessary, receive medical treatment.

Perhaps the most common type of menstrual problem is premenstrual syndrome (PMS). Premenstrual syndrome is believed to be caused by a hormonal imbalance -- either an excess in estrogen or a deficiency in progesterone. An alternative theory concerning the etiology of PMS has identified the gradual withdrawal of endorphins (opiate-like proteins found in the nervous system) as contributing to PMS. Premenstrual syndrome encompasses a variety of emotional, behavioral and physical symptoms.

Due to the large variability in onset during the menstrual cycle, duration of symptoms and severity of symptoms, the identification of an appropriate treatment for PMS is often difficult. Non-pharmacologic treatments that have been shown to be effective include exercise, smoking cessation, weight loss, stress reduction/relaxation therapy, minimizing alcohol intake and a diet high in protein but low in sodium and sugar. If these non-drug therapies are ineffective for a woman, she should consult her gynecologist for treatment.

Exercise and bone health. Osteoporosis refers to premature bone loss and inadequate bone formation, resulting in low bone mass, microarchitectural deterioration, increased skeletal fragility and an increased risk of fracture. The areas of the body most commonly affected by osteoporosis are the hip, wrist and vertebrae. Osteoporosis affects 5 million men and 20 million women in the United States. Research has found that, relatively speaking, women suffer more severely from osteoporosis than men. Women, in general, are at high risk, with older women, Caucasian women and menopausal women particularly susceptible. Other risk factors include smoking, excessive alcohol consumption, a diet low in calcium, anorexia, amenorrhea and steroid use.

Any condition or action that reduces the level of calcium in the bones increases one's risk of osteoporosis. Factors that have been shown to decrease calcium absorption include smoking, consuming caffeine or alcohol, lactose (milk) intolerance and high fiber intake. Treatment includes calcium supplements -- 1000 mg per day in menstruating women, 1,500 mg in menopausal or non-menstruating women. The best source of calcium, however, is food. Eight ounces of milk or four ounces of cheese provides 200 mg of calcium. Tums or oyster-based calcium (calcium carbonate) is also helpful. A practical guideline is that active women who eat less than 2,000 calories daily should supplement their diets with calcium and iron.

Amenorrheic and post-menopausal women may wish to consult their physicians regarding the possible benefits (and risks) of hormone replacement therapy. Sunlight and low-impact weight-bearing (e.g., walking, independent step-action stair climbing) or weight-loading (e.g., strength training, cross training) exercise also help keep bones healthy. It is important to keep in mind that recent evidence suggests that exercise alone is not a sufficient stimulus to prevent the loss of bone mass after menopause. Exercise in combination with estrogen replacement therapy and adequate calcium intake (1,500 mg/day), however, has been shown to effectively protect against post-menopausal-related bone loss. As a preventive measure, women should be encouraged to exercise and eat a nutritious diet during the critical years between adolescence and early middle-age (35), when bone mass is being laid down.

Exercise and menopause

Menopause, commonly referred to as the "change of life," represents the point in time when cessation of menstrual function occurs. Women typically stop menstruating between the ages of 45 and 55. A gradual decline in reproductive function tends to characterize the 10 to 15 years preceding the final menstrual period. Hot flashes are perhaps the earliest sign that a woman is going through menopause. Additional signs of menopause may include any or all of the following: vaginal dryness, a reduced sex drive, urinary incontinence (a problem with urine leakage), weight gain, anxiety, depression and irritability. These alterations can be very unpleasant and disconcerting for many women.

Women in the post-menopausal stage undergo several important hormonal changes -- most notably, a reduction in serum estrogen levels. The greatly reduced ability of the ovaries to produce estrogen during menopause results in significant physiological changes. The loss of estrogen, for example, causes a decrease in the absorption of minerals (e.g., calcium) by the bones. Lower levels of calcium cause the bones to become less dense and weakened, a condition collectively known as osteoporosis. Estrogen deficiency may also place post-menopausal women at a higher risk for heart disease because of its effect on blood lipid-lipoprotein profiles. Specifically, low serum estrogen levels have been associated with elevated lipid levels (cholesterol and triglycerides) and reduced levels of high-density lipoprotein (HDL-C -- the "good" cholesterol carrier that plays a cardio-protective role).

Exercise has been found to have positive effects on several menopausal symptoms. For example, exercise promotes bone mineralization, which helps retard the progression of osteoporosis. Anecdotal evidence and limited research suggest that exercise can also decrease the number and severity of hot flashes. Exercise has also been shown to improve self-image and feelings of confidence, decrease anxiety and depression, and positively contribute to energy levels, quality of sleep and the management of stress in menopausal women.

Post-menopausal women are often instructed to perform pelvic floor (Kegel) exercises. Kegel exercises are designed to improve the tone of the muscles, ligaments and fascia known as the pelvic floor. The pelvic floor controls urination and defecation, enhances the sexual response to orgasm and provides support to the pelvic organs. Many women are unaware that they have muscles in this area that can be strengthened just like their biceps or quadriceps.

Why should a woman pay attention to this small group of muscles? Millions of women are affected by stress urinary incontinence. Stress urinary incontinence is the involuntary loss of urine during physical exertion or activities such as laughing, sneezing or coughing. Unfortunately, many women consider incontinence an inevitable consequence of childbirth and aging, which it is not. Active women of all ages report experiencing incontinence. This can be particularly bothersome when it occurs during physical exertion. In fact, some women stop exercising, change their choice of activity, or begin wearing a protective pad instead of seeking medical advice or beginning a program of Kegel exercises. Strengthening the pelvic floor muscles can provide these women with much needed support and control.

The following serve as basic guidelines for women wanting to perform Kegel exercises:

Contract your anal sphincter as you would to prevent a bowel movement. This can be done while you're standing, sitting or lying down.

Hold the contraction for a count of four seconds, and then relax for four seconds. Don't tighten your abdominal, quadriceps, or gluteal muscles when performing this exercise.

Perform the exercise continuously for a period of five minutes twice a day.

Check to see if you are performing the exercise correctly by placing one finger inside the vagina and feeling the contraction.

It typically takes approximately eight weeks for the Kegel exercises to result in a noticeable improvement in bladder control. Since no other exercise strengthens the pelvic floor muscles as effectively as Kegels, many urinary incontinence experts recommend that all women athletes, including those without stress incontinence, perform five minutes of Kegel exercises daily as a preventive measure.

Don't settle for less

No one could reasonably argue against the fact that exercise can and should be an integral part of a woman's lifestyle. In some situations, the role of exercise is unduly limited by misplaced concern over several special health/medical considerations that exist for physically active women. These special considerations should not, however, dissuade women from participating in sensible exercise programs.

Fortunately, a growing amount of information on the effects and applications of exercise is becoming available, which allows health and fitness professionals to be better equipped to design and supervise exercise programs specifically for women. The key for women who want to increase the likelihood of their living life to its fullest is to seek help from a qualified professional when they have questions regarding exercise and fitness. They should keep in mind that women reap as many, if not more, benefits from exercise as men. The substantial rewards of an active lifestyle can and should be enjoyed by men and women alike. No one should settle for anything less.

REFERENCES

Bachmann, G. "Prevention of menopausal sequelae." New England Journal of Medicine 10(2):359-369, 1991.

Blair, S., et al. "Physical fitness and all-cause mortality: A prospective study of healthy men and women." JAMA 262:2395-2401, 1989.

Bo, K., et al. "Prevalence of stress urinary incontinence among physically active and sedentary female students." Scandanavian Journal of Sports Sciences 11(3):113-116, 1989.

Clark, N. Sports Nutrition Guidebook. Champaign, IL: Leisure Press, 1990. Fletcher, G., et al. "Statement on exercise: Benefits and recommendations for physical activity programs for all Americans." Circulation 86(1):340-344, 1992.

Johnson, M. "Disordered eating." In Agostini, R. (Ed.), Medical & Orthopedic Issues of Active and Athletic Women. Philadelphia, PA: Hanley & Belfus, pp. 141-151, 1994.

Lemcke, D. "Osteoporosis and menopause." In Agostini, R. (Ed.), Medical & Orthopedic Issues of Active and Athletic Women. Philadelphia, PA: Hanley & Belfus, pp. 175-182, 1994.

Marshall, L. "Clinical evaluation of amenorrhea in active and athletic women." Clinical Sports Medicine 13(2):405-418, 1994.

Nattiv, A., et al. "The female athlete triad." Clinical Sports Medicine 13(2):405-418, 1994.

Peterson, J.A., & C.X. Bryant (Eds.), The StairMaster Fitness Handbook (2nd Edition). St. Louis, MO: Wellness Bookshelf, 1995.


James Peterson, Ph.D., FACSM, is a sports medicine consultant, fellow of the American College of Sports Medicine, a former faculty member at the United States Military Academy and a former director of sports medicine for StairMaster Sports/Medical Products Inc.

Baseball I Basketball I Bowling I Cross Country I Fencing I Field Hockey I Football I Golf I Gymnastics I Ice Hockey
Lacrosse I Rowing I Skiing I Soccer I Softball I Swimming I Tennis I Track and Field
Volleyball I Water Polo I Wrestling