PhD M.V. Aranson¹
Associate Professor, PhD E.S. Ozolin¹
Dr.Hab., Professor B.N. Shustin^1
1All-Russian Research Institute of Physical Culture and Sport, Moscow

Keywords: women’s sports, combat sports, trends, analysis, literature.

Introduction. In the present paper, we continue our analysis of the sports science development trends abroad. At this stage, we studied current issues of women’s sports. The work was carried out within the framework of the public task of the Ministry of Sport of the Russian Federation.

Objective of the research was to carry out a scientific analysis of nutrition and recovery characteristics of women in speed and strength sports and identify priority trends of current research in the field abroad.   

Research methods and structure. Over a hundred papers on medical and biological aspects of female athletes' training in combat sports and similar kinds of activity were analyzed. The focus was on works that dealt with nutrition control in women’s sports, along with the articles on recovery methods for female athletes. 

Results and discussion. It is known that eating disorders in sport are most common for women (the so-called “female athlete triad”). This condition is a significant risk factor for a variety of pathologies and increases the athlete’s susceptibility to bone fractures. 

In 2014 the IOC convened a group of experts to update the IOC statement of 2005 with regard to this syndrome. The consensus document [4] replaces the previous one and contains recommendations on risk assessment, treatment and resuming competitive activity. It is recommended to use a new term – “Relative Energy Deficiency in Sport” (RED-S), indicating that male athletes may also experience similar syndrome. RED-S is an impairment of a number of physiological functions including metabolic rate, menstrual function, bone health, immune system, protein synthesis and cardiovascular disease. The reason for it is the deficit of energy and basic minerals, especially calcium. The clinical effect is not just the “triad” of available energy, menstrual function and bone health, but a complex affecting many aspects of physiological functions, health and athletic performance. Working clinical models have also been designed for working with athletes that have the syndrome based on a classification that includes three groups of factors.   

Body weight control is used in many elite sports. In combat sports weight limits are defined by weight categories. These requirements often lead to unhealthy weight loss practices or eating disorders. Research [8] contains a classification of “sports with a high risk of pathological weight control methods to be used” which include the following: aesthetic sports; sports with weight categories; recreational sports; endurance sports; sports in which performance is determined by low body weight. Body weight control can be pathogenic and non-pathogenic. The first type has an emotional component and thus is clearly different from the non-pathogenic, functional control aimed at reaching sports targets. Gradual weight regulation includes limiting food intake, selective eating and exercise; however, it can also have negative consequences. Short-term fast weight loss includes a number of powerful methods that increase the risk of eating disorders. It has been shown that women are more eager to change their constitution and use more pathogenic methods of weight control. They reduce fat intake to the point when their menses cease within a year and the risk of osteoporosis arises. The choice of methods has sexual preferences: women use diets substantially more. With regard to the body structure women more often seek lower weight (50% vs. 10.1% of men). The earlier an athlete begins to control his weight, the more aggressive methods he uses. Thus, pathogenic methods of weight control are used by athletes of both sexes, but their form is different for men and women.      

Iron deficiency is one of the most common nutritional deficiencies, especially in women. Female athletes are more sensitive to iron deficiency compared to their non-active peers, since it is a key element of energy supply systems and oxygen transportation. Researchers from the United States [3] studied the interrelation of iron status and performance in female rowers. It has been shown that the ferritin level of female rowers is closely connected to their performance in 2 km rowing. The authors note that strategies of simple tracking and correction of iron levels may be useful for women at the beginning of the training season, as the iron storage in physically active women depletes with increasing physical loads. Female athletes should be tested for hemoglobin and ferritin levels with the ferritin cut-off of 20-25 mcg/l. The individuals diagnosed with the deficiency should receive recommendations on taking iron supplements.  

Metabolic syndrome is more and more often found in athletes with big body weight. Chinese scientists [5] conducted a cross-sectional study of the cardiometabolic status of heavyweight athletes of both sexes. The syndrome was confirmed based on two standard criteria: CDS (waist circumference; BP; fasting glucose and/or glucose within 2 hours, or diagnosed diabetes; total triglycerides or LDL) and NCEP ATPIII (waist circumference; BP; fasting glucose or diagnosed diabetes; total triglycerides; LDL). Metabolic syndrome is diagnosed if there are three or more criteria in place. It has been shown that the relevant criteria of the disease include values of lean and fat body mass as well as lipid levels (total, LDL and HDL). At the same time the set or criteria used for healthy population cannot be fully applied to athletes; for example, body mass index and volume ratios allow overestimated probability of the metabolic syndrome.    

International team from the university in Brazil [7] studied the speed and range of rapid weight loss in young athletes of both sexes. Immediately after weigh-in athletes filled out a standard questionnaire on hydration and weight loss. Unofficial weigh-in was held twenty-four hours before the competition. Immediately prior to the first fight the levels of sodium, potassium, chlorides and hematocrit were measured. A significant increase in body weight was observed in between the weigh-ins, and it was more significant in women. Rapid weight loss is practiced by 42% of wrestlers; 46.2% of them reported side effects likely worsening the performance. All the biomarkers remained within the normal range during the weigh-in. Wrestlers of both sexes continue to use rapid weight loss despite performance deterioration. A program of educating wrestlers-school students on nutrition and body weight control issues is needed.  

Since there are body weight categories in taekwondo and judo, many athletes reduce their body weight a few days before the competition to get an advantage over their lighter opponents using a variety of methods including supplementation. The purpose of the work done by Egyptian researchers [3] is to determine the effect of choline supplementation on body weight and leptin levels in female wrestlers of various body weight categories. Female athletes of the study group took 2 pills of choline daily for a week before the competition. As a result, a significant difference is noted between the pre- and post-competition periods in terms of leptin levels, free choline in the blood plasma and malondialdehyde in urine; body weight also decreased significantly after the competition. Thus, the use of choline supplementation can lead to rapid weight loss without any side effects in terms of biochemistry of blood and static force.  

Low fat body mass and menstrual cycle disorders in women are associated with low bone mineral density (BMD) [6]. The purpose of this study is to define the relationship between BMD, lean body mass, fat body mass, energy expenditure and menstrual status of female boxers and physically active women with low (C1) and normal (C2) fat body mass. Boxers (11 persons) and control groups (C1 – 16 persons, C2 – 17 persons) aged 18-38 had their body mass index and body composition measured using dual-energy X-ray absorptiometry (DXA). Menstrual status and energy expenditure were assessed using questionnaires. No differences in anthropometric data were found between the boxers and C1 group except for higher lean body mass of the arms in boxers. However, both the boxers and C1 group members had lower fat body mass than C2 group and higher lean body mass index. Energy expenditure of the boxers was higher than that in the control groups. Oligomenorrhea was more common in boxers than in the control groups. Mass index of arms, legs and back was higher in the boxers than in C1 group, and mass index of arms was higher in the boxers than in C2 group members. BMD Z indicators were also higher in the boxers. Higher body mass index gives reasons to believe that boxing has a positive effect on body weight despite the lower fat body mass, high energy expenditure and high incidence of oligomenorrhea.         

Women’s boxing was recognized not a long time ago, and up to date there have not been works studying energy expenditure of female boxers at the national level. The purpose of the research [1] was to assess the energy expenditure of Indian female boxers during sparring. The study involved 20 female athletes. Energy expenditure was assessed using an equation describing the interconnection of HR and oxygen consumption. The results show that the average and maximum energy expenditure taking into account the fight duration reached 12.7±1.3 and 14.4±1.6 kcal/minute. The authors conclude that, depending on energy expenditure, women’s boxing is a highly consuming sport, and further research is needed to help trainers get the necessary information about the energy needs of the female athletes.

Conclusions. Based on the literature analysis the differences of biomedical characteristics of women from those of men as well as specific diseases or pathologies are most interesting for female sports experts. Biomedical control is also important since biochemical and physiological status changes in women are specific and primarily related to the state of the reproductive system. One of the most significant areas is diet correction, since there are a number of alimentary dependent pathological conditions that not only lead to a decrease in efficiency but also threaten the health and lives of female athletes. These include in particular iron and calcium deficiency.  

Most of the studies are conducted by researchers of the countries that are leaders in elite sport. We should note the increasing research activity in the countries where the sports in question are getting to the international level (India, Turkey).

As in other areas of sport science, large-scale studies on sports-related topics are mainly conducted by teams of large educational institutions or specialized sports institutions (sports training academies, research institutes, research laboratories at sports organizations or inter-academic teams). 

References

1. Chatterjee P., Banerjee A.K., Majumdar P. Energy expenditure in women boxing. Kathmandu Univ Med J (KUMJ), 2006, no. 4(3), pp. 319-23.
2. DellaValle D.M., Haas J.D. Impact of Iron Depletion Without Anemia on Performance in Trained Endurance Athletes at the Beginning of a Training Season: A Study of Female Collegiate Rowers. International Journal of Sport Nutrition and Exercise Metabolism, 2011, 21, pp. 501-506.
3. Elsawy G., Abdelrahman O., Hamza A. Effect of Choline Supplementation on Rapid Weight Loss and Biochemical Variables Among Female Taekwondo and Judo Athletes. Journal of Human Kinetics, 2014, vol. 40, pp. 77-82.
4. Mountjoy M., Sundgot-Borgen J., Burke L. et al.  The IOC consensus statement: beyond the Female Athlete Triad – Relative Energy Deficiency in Sport (RED-S). Br J Sports Med., 2014; 48, pp. 491–497.
5. Guo J., Zhang X., Wang L., Guo Y., Xie M. Prevalence of Metabolic Syndrome and Its Components among Chinese Professional Athletes of Strength Sports with Different Body Weight Categories. PLoS ONE, 2013 8(11): e79758. doi:10.1371/journal.pone.0079758.
6. Trutschnigg B., Chong C., Habermayerova L., et al.  Female boxers have high bone mineral density despite low body fat mass, high energy expenditure, and a high incidence of oligomenorrhea. J. Appl Physiol Nutr Metab., 2008, no. 33(5), pp. 863-9.
7. Viveiros L., Moreira A., Zourdos M.C., et al. Pattern of weight loss of young female and male wrestlers. J Strength Cond Res., 2015, no. 29(11), pp. 3149–3155
8. Werner A., Thiel A., Schneider S., et al. Weight-control behaviour and weight-concerns in young elite athletes – a systematic review. Journal of Eating Disorders, 2013, no. 1, p. 18.

Corresponding author: vniifk@yandex.ru

Abstract

 Studies carried out in recent years showed that information on trends in Olympic sports training technologies is in demand with sports professionals of various levels. However, the supply of information about most important trends of scientific research in elite sport to experts is still limited. The analysis of contemporary literature on training female athletes enabled us to identify priority areas of the current research in this field abroad. The use of extratraining factors, in particular diet optimization and recovery means, is such an area. The article presents research data of foreign experts on the subject.