Dr. Biol., Professor R.V. Tambovtseva¹
Postgraduate student K.V. Sergeeva^1
1Russian State University of Physical Education, Sport, Youth and Tourism (SCOLIPE), Moscow

Keywords: women’s powerlifting, hormones, estradiol, testosterone, prolactin, cortisone, physical workload, available energy resource, dietary supplements, menstrual cycle disorders, lean body mass.

Background. The modern women's weightlifting, powerlifting and bodybuilding sports are getting increasingly popular the world over. The sports elite training systems need to be well designed an managed to prevent a variety of ovarian-menstrual cycle disorders including oligomenorrhea, amenorrhea and anovulatory cycles and other pathologies of many detrimental effects on the sporting women’s health standards. Some sport researchers believe that the ovarian-menstrual cycle disorders may be interpreted as the natural adaptation to the growing metabolic demand in the energy-intensive sports disciplines that cannot be satisfied by the low-energy traditional diets [7]. Thus the women’s weightlifting sport elite is known to claim around 700-900 kcal per training session on average, with the top-class athletes’ energy demands coming to 1500 kcal at times [1]. There are reasons to assume that the energy-inefficient diets in the modern women's weightlifting, powerlifting and bodybuilding sports may be among the key reasons for the menstrual cycle disorders due to the energy deficiencies.

Objective of the study was to analyze benefits of a dietary control and workload management model for the women’s powerlifting sport elite.

Methods and structure of the study. The model testing experiment was run at the Volkov Sport Biochemistry and Bioenergy Department’s Bioenergy Laboratory at the Russian State University of Physical Education, Sport, Youth and Tourism (RSUPESYT). We sampled the 22-29 year old elite women powerlifters (n=14) for the experiment that took two 5-week periods (Mesocycles 1 and 2) making up 80 days in total. The model testing experiment was designed to collect the following individual information and test data: background, sporting record, gynecological health record, training progress test data, dieting record, body mass, body length, fat mass, body mass index (BMI/ Quetelet index); and the hormonal functionality test data including the estradiol, prolactin, cortisol, testosterone, luteinizing hormone and follicle-stimulating hormone test profiles. We used the radioimmunoassay method with the morning blood sampling from the median cubital vein after every two training days. The tests were timed to the follicular phase starting point on the third day of a menstrual cycle. On the whole, every subject was tested prior to, in the middle of (end of Mesocycle-1) and after (end of Mesocycle-2) – with the tests referred to herein as the pre-, mid- and post-experimental tests, respectively. The training energy costs were computed as provided by N.N. Saksonov [3]. The main metabolism was profiled as recommended by the International Sports Sciences Association [5], with the daily energy demands computed using the relevant timetables – that give the energy demand rates classified by the physical work classes and work times [2].

Results and discussion. Mesocycle-1 diet was limited to 19.6 kcal/kg of lean body mass (LBM) ^-1/day^-1; with the available energy resource of 19.6 kcal/ kg lean body mass secured by 1470 kcal/day or 27.4 kcal/ kg lean body mass ^-1/day^-1; with the training-day energy demand rated at 420 kcal, i.e. 7.8 kcal/kg lean body mass ^-1/day^-1; and available energy resource = (1470 kcal - 420) / 53.5 lean body mass = 19.6 kcal. The experiment was designed to reduce the body mass and increase the workload; and this is why the mid-experimental available energy resource was tested at 20 kcal/ kg lean body mass ^-1/day^-1. The daily energy demand totaled 2473 kcal, with the total energy deficit estimated at 1000 kcal.

Mesocycle-2 diet was balanced at 25.8 kcal /kg lean body mass ^-1/day^-1; with the calorific value increased by 300 kcal /day to 1770 kcal/ day or 34.1 kcal/ kg lean body mass ^-1/day^-1; with the training-day energy demand rated at 430 kcal; and available energy resource = (1770 kcal - 430) / 51.9 lean body mass = 25.8 kcal. The daily energy demand totaled 2380 kcal, with the total energy deficit of 610 kcal (25%). Due to the lean body mass and workload growths, the post-experimental available energy resource was tested at 25.3 kcal /kg lean body mass ^-1/day^-1.

The pre-, mid- and post-experimental body composition tests showed the following variations: body mass: 65.2 kg to 62.1 kg to 62.9 kg; adipose tissue: 18.1% to 16.5% to 16.5%; and lean body mass: 53.5 kg to 51.9 kg to 52.6 kg, respectively.

A hormonal profile is considered the key criterion of the individual reproductive health, with the healthy menstrual cycle rhythm known to be controlled by secretion of the ovarian hormones stimulated by pulsations of the luteinizing hormone / follicle-stimulating hormone pituitary gland hormones.

The mid-experimental tests found the available energy resource falling to 19.6 kcal/ kg lean body mass – well below the recommended level of 25-30 kcal/ kg lean body mass for the whole Mesocycle-1 – to force the hormones drop below the reference levels. In Mesocycle-2 the available energy resource was tested to grow above 25 kcal/ kg lean body mass by only 300 kcal, while the training process intensity was even increased to a degree.

The typically hypothalamic sports-specific amenorrhea is caused by a low secretion of gonadotropic follicle-stimulating hormone / luteinizing hormone hormones, with the luteinizing hormone level being the key indicator of the GN-RH pulse generator that controls the ovarian function and, hence, may be viewed as the reproductive health indicator. The tests found the highest variations in the luteinizing hormone and estradiol contents. The pre- versus mid-experimental tests found the serum luteinizing hormone levels falling from 8.38 to 1.82 mIU/ ml, and estradiol levels from 33.2 to 5.9 pg/ ml (78% and 82% falls), respectively. It may be assumed that the hypothalamic-pituitary-ovarian line was blocked by hypothalamus, as evidenced by the fall in the serum luteinizing hormone content.

The dietary calorific value growth by only 300 kcal/ day (an equivalent of 25 kcal/ kg lean body mass with the total energy deficit of 610 kcal) – caused the luteinizing hormone to grow to 17.21 mIU/ ml, i.e. by 845%. This progress shows benefits of the experimental model as verified by the luteinizing hormone growth to the amenorrhea-free level. Such luteinizing hormone growth in the amenorrhea-diagnosed women is believed to be indicative of the hypothalamic functionality recovery process followed by the menstrual function coming back to normality.

The post-experimental tests found the serum cortisol slightly growing to exceed the norm by hundredths. Generally growths of the blood adrenal hormones are interpreted as indicative of the workload-specific stressors or carbohydrate deficiencies. Our tests and analyses did not confirm the stress hypothesis that explains the stimulation of the hypothalamic-pituitary-adrenal line and the associating high cortisol/ prolactin levels by reproductive line suppression. The study data and analyses showed that the hormonal system malfunctions and the menstrual cycle disorders are caused by the low-energy/ available energy resource diets rather than the training process mismanagements; and that the reproductive dysfunctions may be viewed as the energy-saving adaptations to the energy-deficient diets.

The biochemical test data show that sporting women are suffering from the chronic energy deficits. The metabolic substrates and hormones rating tests demonstrate that the amenorrhea-diagnosed women tend to adapt to the chronic deficits of energy and carbohydrates by the fat reserve mobilizing, glucose digestion depressing and metabolic processes slowing mechanisms. This means that their diets fail to cover the energy costs claimed by the physical activity, with this situation being typical for most of the sporting women – as verified by the studies that show such athletes’ energy balances being negative despite the body mass being stable [4, 6]. The chronic carbohydrate deficiencies are diagnosed by ketone bodies tested in urine; whilst the levels of blood ketone bodies are indicative of the fat oxidation rates, with the body being forced to mobilize the fat reserves to cover the carbohydrate deficits.

The study demonstrates that the energy-control dieting model may be an efficient non-pharmacological method to cure the sports-specific amenorrhea. Diet optimizing models can help restore the normal hormonal levels and menstrual cycles of the amenorrhea-diagnosed athletes, with the associating benefits for the metabolic balance and competitive performance.

Conclusion

• When the energy costs and intensities of trainings stay unvaried, the women athletes may still be at risk of hormonal imbalances due to the energy-deficient/ imbalanced diets.

• It is the low calorific values and low avilable energy resource rather than the training system mismanagements that are responsible for the hormonal dysfunctions and menstrual cycle disorders.

• When the avilable energy resource is low, the gonadotropin hormone generation by hypothalamus is slowed down and the secretion of luteinizing hormone by the pituitary gland is inhibited.

• Non-pharmacological therapeutic methods alternative to the hormonal therapy, with their prudential dietary control and management tools, may help restore normal hormonal levels and menstrual cycles in amenorrhea-diagnozed women athletes.

References

1. Gorulev P.S., Rumyantseva E.R. Women's Weightlifting: Problems and Prospects. Study guide for students majoring in 032101 (022300): SC RF PCS. M.: Sovetskiy sport publ., 2006. 162 p.
2. Datsenko I.I., Gabovich R.D. Preventive medicine. General hygiene with basics of ecology. Study guide. Kiev: Zdorovye publ., 1999. 694 p.
3. Saksonov N.N. Weightlifter Energy Consumption: Lecture for correspondence students of institutes of physical education, students of refresher courses, trainers and weightlifting teachers. SCOLIPE publ.. M., 1980. 22 p.
4. Trappe T.A.  [et al.] Energy expenditure of swimmers during high volume training/Medicine and Science in Sports and Exercise. 1997. Vol. 29, no.7. pp. 950–954.
5. Hatfield F.C. Fitness: The complete Guide: Official Text for ISSA's Certified Fitness Trainer Program. International Sports Sciences Association. Edition 8.6.6.  Саrpinteria: ISSA, 2013. 735 р.
6. Hill R.J., Davies P.S. Energy intake and energy expenditure in elite lightweight female rowers. Medicine and Science in Sports and Exercise.  2002. Vol. 34, no.11. pp. 1823–1829.
7. Wikström-Frisén L. Training and hormones in physically active women with and without oral contraceptive use. Umeå University. Umeå, 2016. 82 p.

Corresponding author: ritta7@mail.ru

Abstract

Women's weightlifting, powerlifting, and bodybuilding are rapidly developing nowadays. Objective of the study was to analyze the effects of various levels of available energy on the hormonal profile and menstrual function of females engaged in powerlifting with dietary modifications but without reducing the volume and intensity of physical loads. The study involved the 22-29 year-old highly-qualified female athletes specializing in powerlifting (n=14). The experiment lasted 80 days and included two 5-week stages (mesocycles). A general, sports and gynecological history was taken. The radioimmunoassay technique was used. The blood samples were taken from the median cubital vein in the morning after two days of training. The measurements were taken at the beginning of the follicular phase, on the 3rd day of the menstrual cycle and three times during the experiment: at the beginning of the study, at the end of the first mesocycle and at the end of the second mesocycle. Energy costs during the training sessions were calculated by the method of N.N. Saksonov. The amount of energy spent during the day was calculated based on the special timing tables.

It is shown that physical load, as a stress factor, does not have an inhibitory effect on hormones, while a low energy availability level violates the rhythm of hormone secretion. The insufficient level of available energy slows down the release of the gonadotropin-releasing hormone by the hypothalamus and blocks the secretion of luteinizing hormone by the pituitary gland.