Dr.Biol., Professor R.V. Tambovtseva¹
I.A. Nikulina^1
1Russian State University of Physical Education, Sports, Youth and Tourism (SCOLIPE), Moscow

Keywords: hormones, glucocorticoids, physical working capacity (PWC), track and field athletes, urine, blood.

Introduction.Changes in physical working capacity (PWC) during sports training are directly associated with metabolic reorganization, changes in the quantitative and qualitative correlations between various biochemical processes, improvement of different regulatory mechanisms [1, 2, 4, 5]. Adaptive changes in metabolic activity, including energy metabolism, during regular training activities occur not only in the working muscles, but also in many other organs and tissues [3]. An important role in maintaining biochemical homeostasis is played by the hormone assembly introduced by a synergistic action of corticosteroids, catecholamines, insulin, glucagon, somatotropin, thyroxin and other endocrine factors affecting metabolism [8, 9]. The hormone level in the bodily organs and tissues is the result of metabolic activity and energy exchange, as well as activity of the organs involved in the process of metabolism. The dynamics of changes in the concentrations of hormones is used to characterize the adaptive reorganization of metabolism under the influence of physical loads [1, 2]. Despite the fact that the scientific literature presents a wealth of valuable material on the changes occurring in the hormonal status under the influence of physical loads, to date there is a lot of contradictory information about the effects of training on hormonal metabolism during muscle activity. According to numerous studies, the results of which contradict each other, different loads were used in the tests, where their volume and intensity were not accurately recorded. Therefore, of special interest for the purpose of the study is a hormonal response of the body of trainees to standardized loads, the power and duration of which are accurately recorded. Since one and the same metabolic effect can be achieved through different regulators, and individual differences in the body's response to muscular work of different nature can vary greatly, a comprehensive analysis of changes in the activity of the endocrine glands and energy systems of the body takes on particular importance.

Objective of the study was to analyze the hormonal control mechanisms behind the total activity of glucocordicoids in the adrenal cortical system in the low- and highly-trained middle-distance racers in different training periods.

Methods and structure of the study. The study was performed at the Muscular Activity Bioenergetics Research Laboratory of the N.I. Volkov Sport Biochemistry and Bioenergetics Department of the Russian State University of Physical Education, Sports, Youth and Tourism, Moscow. Subject to the experiment were two groups of male middle distance runners: Group 1 was made of the highly-trained athletes (n=21); Group 2 - of the athletes having the qualification not higher than Class III (n=12). Group 1 participated in the experiment at the beginning of the precompetitive period of the training macrocycle, when the amount of load in the training session equaled 60% of the maximum load planned for one lesson within this macrocycle. They were re-examined at the beginning of the competitive period, when the amount of load in the training session was already 80% of the maximum. Group 2 was tested after a 3-month-long break in training. During the training sessions, they were to perform high-intensity and submaximal specific dynamic loads. The track and field athletes of this group performed the load corresponding to the one applied during re-examination of Group 1, which was obviously high for Group 2. In laboratory conditions, all athletes were subjected to the step test "to failure": step duration - 3 min, initial power - 1 W per kg of body weight, surplus level - 1 W. The Reference Group made of the untrained males (n=10) participated in the experiment as well. At the time of the examination all subjects were healthy and signed their informed consent to participate in the study.

The experiments under the study were designed to obtain the following test data: urinal excretion of neutral 17-ketosteroids (17-KS); 17-ketogenous steroids (17-KGS); and free and total 17, 21-dioxi-20- ketosteroids (17-OKS). The study of these hormones enables to assess the functional activity of the adrenal cortex and secretion of male sex hormones. Urine was tested prior to and 10 min after the loads, with the 17-OKS and 11-OKS levels tested in the peripheral blood plasma. Venous blood for the tests was sampled prior to, straight after and 3/ 10 minutes after the physical trainings. We applied he methods of an immunochemiluminiscent analysis and fluorometry.

Results and discussion. Included in Table 1 are the data on the daily excretion of urine 17-KS and 17-KGS on training days and days-off in the highly-trained track and field athletes and low-trained middle-distance racers.

 

Table 1. Daily excretion of urine steroid hormones (17-KS and 17-KGS) in highly- and low-trained track and field athletes and untrained males

Subjects	Group	17-KS (mg per day)	17-KGS (mg per day)
Reference Group	-	15.43+0.61	10.81+0.61
Highly-trained track and field athletes at the beginning of the precompetitive period	1	14.89+1.12	13.31+0.54**
	2	14.23+1.26	9.64+0.52
Highly-trained track and field athletes at the beginning of the competitive period	1	16.91+0.53	13.03+0.82**
	2	17.12+0.63	10.11+0.74
Low-trained track and field athletes	1	15.90+1.11	11.83+0.66***
	2	14.41+1.23	17.15+0.31

Note: ** – significance level р<0.05; *** – р<0.01. 1 – training day test data; 2 – day-off test data.

 

It was found that the athletes' motor modes did not differ statistically significantly in terms of the mean values of daily excretion after the training session and in the absence of one. In the precompetitive period, there was a certain downward trend (p<0.1) in the daily excretion of 17-KGS under training load compared with the same period of time without exercise. At the beginning of the competitive period, when the amount of load during the training session was higher than in the precompetitive period, the differences became significant (p<0.01). The poorly trained racers were tested with more than 1.5-times growth of the post-training 17-KGS excretion versus the day-off test data: from 11.83+0.62 to 17.19+1.3 mg/day (p<0.01).

Table 2 presents the data on the effects of training load on the blood level of oxycorticosteroids in the track and field athletes, namely, the mean values of the pre- and post-training levels.

 

Table 2. Effects of training load on blood level of oxycorticosteroids (17-OKS μg%) in track and field athletes having different qualifications

Subjects	Parameter	ХΔ	Sx	pt	p	% of changes
Highly-trained track and field athletes (precompetitive period)	17-OKS	+3.90	1.21	3.238	<0.01	+31.4
Highly-trained track and field athletes (competitive period)	17-OKS	+3.14	1.15	3.643	<0.01	+22.7
Low-trained track and field athletes	17-OKS	+2.09	1.62	1.298	>0.2	-

The table data indicate that training loads of 60% and 80% of the maximum macrocycle volume contributed to an increase in the blood level of 17-OKS in the highly-trained athletes (by 31.4 and 22.7%, respectively). While in the low-trained athletes, the heavy training load of 80% did not cause any changes in the level of these hormones in the blood plasma.

Consequently, the intensity and volume of physical load used in the experiment was sufficient enough to stimulate the activity of the hypothalamic-pituitary-adrenocortical system. Therefore, it was fair to assume that there would be corresponding changes in the content of 17-OKS in the blood plasma and in the indicators of urinary excretion of 17-KS, 17-KGS and 17-OKS. The specific training loads revealed the differences of the low- and highly-trained athletes in the 17-OKS excretion rates that were found to grow in the highly-trained athletes versus the stable levels in the low-trained athletes. Thus, it might be suggested that the tissue capacity to bind hormones is a function that can be developed through training. A decrease in the amplitude of hormonal shifts in the trained athletes versus the untrained ones is only possible under standard loads, the power of which is relatively small. High intensity work "to failure" or steady loads, which cause profound changes in the energy metabolism, require considerable activation of the regulatory mechanisms. The decrease in the concentration of a number of hormones under physical load, including steroid ones, does not necessarily indicate their decreased function. This may be due to the receptor binding and intensification of exchange of the regulators themselves.

Conclusion. The analysis of the athletes' motor mode did not reveal any statistically significant differences between the mean values of the daily excretion ​​after the training session and in the absence of one. In the precompetitive period, the athletes demonstrated a downward trend in the daily post-training 17-KGS excretion compared to the same period of time without exercise. At the beginning of the competitive period, the increase in the amount of training load during the training session resulted in the appearance of statistically significant differences in the athletes. The poorly trained racers were tested with more than 1.5-times growth of the post-training 17-KGS excretion versus the day-off test data. The specific training loads revealed the differences of the low- and highly-trained athletes in the 17-OKS excretion rates that were found to grow in the highly-trained athletes versus the stable levels in the low-trained athletes.

 

References

1. Kremer U.J., Rogol A.D. Endokrinnaya sistema, sport i dvigatelnaya aktivnost [Endocrine system, sport and motor activity]. Kiev: Olimpiyskaya Literatura publ., 2005, 599 p.

2. Newsholm E., Start K. Regulyatsiya metabolizma [Regulation of metabolism]. Moscow: Mir publ., 1977.

3. Pogodina S.V., Aleksanyantz G.D. Adaptatsionnye izmeneniya glyukokortikoidnoy aktivnosti v organizme vysokokvalifitsirovannykh sportsmenov razlichnykh polovozrastnykh grupp [Adaptive changes in glucocorticoid activity in elite athletes of different sex and age groups]. Teoriya i praktika fiz. kultury, 2016, no. 9, pp. 49-52.

4. Tambovtseva R.V., Nikulina I.A. Izmenenie gormonalnoy regulyatsii obmennykh protsessov u konkobezhtsev na raznykh etapakh trenirovochnogo tsikla [Changes in hormonal regulation of metabolic processed in speed skaters in different phases of training cycle]. Teoriya i praktika fiz. kultury, 2015, no. 5, pp. 52- 54.

5. Tambovtseva R.V., Nikulina I.A. Osobennosti gormonalnoy regulyatsii energeticheskogo obmena u sportsmenov razlichnykh spetsializatsiy pri vypolnenii predelnoy raboty [Specifics of hormonal regulation of energy metabolism in athletes in various disciplines when training to failure]. Teoriya i praktika fiz. kultury, 2016, no. 1, pp. 28-30.

    Corresponding author: ritta7@mail.ru

 

Abstract

Objective of the study was to analyze the hormonal control mechanisms behind the total activity of glucocordicoids in the adrenal cortical system in the low- and highly-trained middle-distance racers prior to the precompetitive and competitive periods. Experiments under the study were designed to obtain the following test data: urinal excretion of neutral 17-ketosteroids (17-KS); 17-ketogenous steroids (17-KGS); and free and total 17, 21-dioxi-20- ketosteroids (17-OKS). Urine was tested prior to and 10min after the loads, with the 17-OKS levels tested in the peripheral blood plasma. Venous blood for the tests was sampled prior to, straight after and 3/ 10 minutes after the physical trainings. The study data and analyses showed significant differences in the test data with the growth of the training loads prior to the competitive period. The poorly trained racers were tested with more than 1.5-times growth of the post-training 17-KGS excretion versus the day-off test data. The specific training loads revealed the differences of the low- and highly-trained athletes in the 17-OKS excretion rates that were found to grow in the highly-trained athletes versus the stable levels in the low-trained athletes.