Editor’s Note: This post was originally published March 2014 and has recently been updated and revised for accuracy and comprehensiveness.
It is estimated that up to 45 percent of female athletes in certain sports experience menstrual irregularity, also referred to as Athletic Amenorrhea. Within the last 20 years, our society has witnessed a significant increase in the level of athletic participation by women and as a result, women are more aware of the changes experienced in their menstrual cycle.
There is highly regarded speculation that in some way the female body “senses’ when energy reserves are inadequate to sustain a pregnancy and thereby ceases ovulation to prevent conception. Research has defined a level of body fat of 11 percent as the “critical level” for the onset of menstruation. This level varies plus or minus 4 percent in many healthy, active females. During the past four years there has been an abundance of studies indicating a high incidence of menstrual irregularities among women athletes.
Evidence has demonstrated that chronic, high-intensity exercise stimulates profound changes in the menstrual cycle. At the same time, an increase in the level of testosterone in the blood stream of women who engage in strenuous physical activity has been noted. It is theorized that the mass of body fat relative to lean body weight is a critical factor in the onset of secondary amenorrhea. This condition is clinically defined as the absence or suppression of menstruation from any cause other than pregnancy or menopause.
The term amenorrheic refers to women whose menstrual cycles occur at intervals of longer than 90 days, and is the only clinical symptom to indicate a disruption of the reproductive system. Female athletes generally have a percentage of body fat lower than 20 percent, and competitive body builders can reach as low as 10 percent. The average non-athletic woman’s body fat varies between 22-28 percent, with a level of above 30 percent considered obese.
Evidence has demonstrated that chronic, high-intensity exercise stimulates profound changes in the menstrual cycle.
Factors Leading To Amenorrhea
Some of the factors which lead to the irregular occurrence of the menstrual cycle, include the following:
- Low body fat (below 12 percent).
- Early pre-pubertal athletic training.
- Decreased hypothalamic activity.
- Intensity of training regimens.
- Reproductive maturity.
- Stress (mental as well as physical).
- Diet, (a high protein, low-carbohydrate diet can disrupt menstrual cycle).
- Anabolic steroid usage: the Influx of male hormones, whether synthetic (Anavar, Deca-Durabolin, etc.) or testosterone, can wreck havoc on a woman’s body.
- Severe exercise (heavy weight training or long-distance running).
Changes in the Body
There are several changes that occur in the female who is experiencing amenorrhea because of strenuous exercise. These include a decrease in ovarian function and metabolic and hormonal changes (the ratio of estrogens to androgens in the body).
It is known that Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH), both of which are involved in the onset of ovulation, increase in concentration in the blood before exercise. Critical changes are taking place in the hypothalamus, and the pulse frequency of the gonadotrophin-releasing hormone is altered. All this activity is related to the changes in insulin receptor sensitivity in the hypothalamus. The potential for long-term effects on women who experience chronic amenorrhea are as follows:
A lower bone-mineral content, which can lead to reduced bone mass and the earlier onset of osteoporosis.
The potential for a female athlete’s inability to become pregnant. Studies show that women runners who develop amenorrhea have decreased spinal bone mineral content. The magnitude of the loss appears to be related to the duration of the amenorrhea.
Research at the University of California, San Francisco, was conducted to determine whether the bone loss was gradual, as in the aging process, or rapid at first and then slower, as in menopause. Bone loss (osteoporosis) makes bones easily susceptible to breaking.
One Probable Cause: Low Levels Of Calcium.
Lowered calcium levels have been found in women who restrict their carbohydrate! Caloric intake while increasing their protein intake. Research has demonstrated that high protein intake is related to lower calcium levels. Estrogen levels drop dramatically when a woman ceases to menstruate.
Forty women runners, ranging in age from 18 to 40 had their bone mineral content checked. These athletes had been experiencing amenorrhea for six months up to ten years. Those who had been amenorrheic for less than three years lost approximately 4.2 percent of their bone content during the year. The longer-term amenorrheic women lost an insignificant amount of bone. This study concluded that significant bone loss occurs during the first years of amenorrhea and tapers off in the chronic amenorrheic athlete.
It is important to stress that women athletes should consult their physicians immediately if menstruation ceases. In order to prevent irreversible bone damage, it is important to follow the directions and suggestions below.
Directions and Suggestions
The potential for side effects for women experiencing amenorrhea as a result of strenuous exercise has been found to be more pronounced in the leaner and lighter athletes. Pharmacological treatments can include prescribing Clomiphen citrate, a non-steroidal anti- estrogen drug that acts to stimulate the ovaries or estrogen replacement.
This type of intervention should be used on the advise of a gynecologist or endocrinologist, as these drugs do have potential side effects. A more sensible approach to reversing an irregular menstrual cycles (oligo-menorrhea) or a complete cessation of menses (amenorrhea) would be to follow some basic tips. Try to cycle your training by using lesser intensity during the off- season and allowing the body to return to its critical fat level (approximately 13 percent) during the off -season.
Nutritionally, there are several supplements (amino acids, vitamins, and minerals) that have been found to help during these months of irregular cycles.
L-Tyrosine (free form), 800 mgs per capsule, two capsules 20 minutes before breakfast and at mid-afternoon. Taking four to six ounces of fruit juice will enhance the uptake of this and all amino acids.
L-Glutamine, 500 mgs per capsule two capsules twice a day, mid-morning, and mid-afternoon. This amino acid assists in maintaining blood sugar levels, while improving overall gastrointestinal health.
Multi-vitamin mineral: One capsule three times a day with meals. Be sure this product is yeast -sugar- and starch- free.
Based on available research, it appears that exercise-associated disturbances in menstrual function can be reversed with moderate changes in life-style without serious consequences as long as the condition does not persist indefinitely. In order to accomplish their short-term goals, it is important for female athletes to establish peace of mind to continue competing and training without causing any long-term health effects. With this in mind, female athletes can participate in the activities of their choice and live in harmony with their sports as well as their bodies.
If you are a Certified Personal Trainer or Coach, and work with female athletes, the AFPA Sports Nutrition Consultant Certification program would be an excellent course to learn more about Athletic Amenorrhea and how to effectively guide your athletes to health, wellness and optimal performance.
- Wakat. D.K. Et Al. Reproductive System Function In women cross-country Runners. Med. Sd. Sports Exec. 14:263. 1982.
- McArdie, wd., Et Al. Exercise Physioiogy. Energy, Nutrition, And Human Performance. Second Edition, Lea & Febiger, 1986.
- Caicbrese. L.H., Et Al. Menstrual Abnormaiities. Nutritional Patterns. And Body composition in Female Baud Dancers. Phys Sports Med. 11(2)86,1983.
- Cariberg, KA. Et Al: Body composition of OiigolAmenorrheic Athletes. Med. Sci. Sports Exec., 15:21 5, 1983.
- Shangoid, M.M.. Do women’s Sports Lead To Menstrual Problems’ contemp. Obst. Gynecol., 17:52, 1981.
- Builen, BA., Et Al., Endurance Training Effects On Plasma Hormonal Responsiveness And Sex Hormone Excretion. 1. AppI. Physiol. 5-/14 53. 1984.
- Moseby’s Medical Dictionary, 1984.
- 8 Durin. J.V.G.A. Et Al. Assessment Of The Amount Of Fat In The Human Body FromMeasurements Of Skin-Fold Thickness. British 1 Nutri., 21:681,1967.
- Moseby’s Medical Dictionary. 1984.
- Jaffe, RB. Irreversible Bone Loss Paper Presented, Am college Sports Med. 1986.
- Freedson, Rs., El Al. Physique, Body composition, And Psychological characteristics Ofcompetitive Female Bodybuilders Phys. Sports Med., 11(5), 1983.
- Moseby’s Medical Dictionary, 1984.
- McArdle, W.D. EIAI. 1986.
- Hutnagel. v. No More Hysterectomies, Nat Books, New American Library. 1988.
- Bonen. A. Athletic Menstrual cycle Irregularity Endocrine Response To Exercise AndTraining, Phys Sports Medicine. 12.78-94, August 1984.
- Shangold, M.M.. Concerns of Athletic Women About Reproduction Function. MedicalAspects Sexuality, 17:146-154, Dec. 1983
- Cooper, K Antioxidant Revolution. Thomas Nelson Pub. 1994.
Author: Mark J. Occhipinti, Ph.D.,ND