American Fitness Professionals & Associates

By: Mark Occhipinti, M.S., Ph.D., NDc

Within the last twenty-five years, our society has witnessed a significant increase in the level of athletic participation by women.
As a result of this, women are more aware of the changes they are experiencing in their menstrual cycle. It is estimated that from 45% of female athletes in certain sports, (body-building ballet dancing, track and field, etc.) experience menstrual irregularity.
There is highly regarded speculation that in some way the body “senses” when energy reserves are inadequate to sustain a pregnancy and thereby ceases ovulation to prevent conception. 2
Research has defined a level of bodyfat of 11% as “critical level” for the onset of menstruation. This level varies plus or minus 4% in many healthy active females. 3-4
There has been a plethora of studies indicating a high incidence of menstrual irregularities among women athletes during the past four years.

Evidence has demonstrated that chronic exercise of higher intensity stimulates profound changes in the menstrual cycle. 5
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. 6 It is theorized that the mass of bodyfat 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.7

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 bodyfat below 20%, and competitive body builders can reach as low as 10%.
The average non-athletic woman’s bodyfat varies between 22-28%, with a level of above 30% considered obese. 8

FACTORS LEADING TO AMENORRHEA

Some of the factors which lead to the irregular occurrence of the menstrual cycle include the following:

1. Low body fat (below 12%).
2. Early pre-pubertal athletic training
3. Decreased hypothalamic activity.
4. The intensity of training regimens.
5. Reproductive Maturity.
6. Stress (mental as well as physical stress).
7. Diet, ( a high protein, low-carbohydrate diet can disrupt menstrual cycle).
8. Anabolic steroid usage: the Influx of male hormones, whether synthetic ( Anavar, Deca-Durabolin, etc.) or testosterone, can wreak havoc on the woman’s body.
9. 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 as a result of strenuous exercise.
These include:
1. A decrease In ovarian function.
2. Metabolic and hormonal changes (the ratio of estrogen’s to androgens in the body).

HORMONAL CHANGES

It is known that Luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) which are both involved in the onset of ovulation, increase in concentration in the blood prior to exercise. 9 Critical changes are taking place in the hypothalamus, and the pulse frequency of gonadotropin-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 the woman who experiences chronic amenorrhea are as follows:

1. A lower bone-mineral content, which can lead to reduced bone mass and the earlier onset of osteoporosis.

2. The potential for the female athlete not 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.

3. 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. High protein intake has been demonstrated in the research 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 from six months up to ten years. Those women who had been amenorrheic for less than three years lost approximately 4.2% of their bone content during the year. The longer-term amenorrheic women lost an insignificant amount of bone. This research 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 consult their physicians immediately if they stop menstruating. The directions and suggestions below are Important to follow to prevent or reverse bone loss or the decrease in bone mass may become Irreversible. 10

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. 11  
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 only be conducted by your gynecologist or endocrinologist, as these drugs do have potential side effects. 12 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%) during the off -season. 13
Nutritionally, there are several supplements (amino acids, vitamins, and minerals) that have been found to help during these months of irregular cycles. 14

CONCLUSION

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 is not permitted to persist indefinitely. It is important for female athletes to establish peace of mind to continue competing and training without causing any long-term health effects while still accomplishing their short- term athletic goals. With this in mind, female athletes can participate in the activities of their choice and live in harmony with their sports and their bodies as well.
Bibliography

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15. Bonen, A. Athletic Menstrual Cycle Irregularity: Endocrine Response To Exercise And Train-ing, Phys.  Sports Medicine. 12:78-94, August, 1984.
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17. Cooper, K. Antioxidant Revolution, Thomas Nelson Pub. Nashville, Tn 1994
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