Dr.Hab., Professor E.A. Shirkovets¹
PhD, Associate Professor I.L. Rybina²
Dr.Hab., Professor B.N. Shustin^1
1All-Russian Research Institute of Physical Culture and Sport, Moscow
 ²Republican Research and Practical Neurology and Neurosurgery Centre, Minsk, Republic of Belarus

Keywords: elite athletes’ fitness criteria, practical recommendations.

Introduction. In an increasingly competitive environment in cyclic sports the issue of optimizing the training of athletes based on the analysis of the complex of objective data on the state of the body’s systems is the most pressing one [1, 3]. Development and improvement of the recommendations covered in the work are based on the study of athletes’ body responses to exercise performed at various stages of training. Such studies are particularly relevant in elite sport.

Determining the type of non-specific adaptive responses provides the necessary information for forecasting the effectiveness of corrective measures as well as the diagnostics of possible health disorders of athletes and their prevention [2, 4, 5]. Practical recommendations are developed on this basis with regards to the use of elite athletes’ special fitness criteria.

Objective of the study was to analyse elite athletes’ special fitness and adaptive body responsiveness rating criteria.

Research results and discussion.

1. Bio-energetic markers of special working capacity

In the physical loads classification in terms of bio-energetic criteria it is advisable to single out five basic zones that differentiate training loads based on their primary effects on various functional systems of the body:

– exercising in the first intensity zone is mostly provided by lipid energy sources, training at the aerobic threshold level (lactate – 2-3 mmol/l) is used in the beginning of the training period for increasing the aerobic capacity indicator;

– the second muscle load intensity zone (lactate 3-4 mmol/l, the anaerobic threshold zone) is used for comprehensive improvement of aerobic capacity;

– training sessions in the third zone (zone of mixed effects of physical loads, lactate – 4-8 mmol/l) contribute to the development of the aerobic functions capacity; this zone is divided into two subzones for a more specific effect on the systems of the body, the loads in the first subzone have more to do with the development of aerobic capacity (lactate  - 4-6 mmol/l),  lactate production in the second one increases to 8-9 mmol/l;

– the fourth intensity zone in terms of the training loads is the zone of priority development of the anaerobic (glycolytic) capacity; in the elite athletes’ training practice it is divided into three subzones: the blood lactate level ranges from 8 to 12 mmol/l in the first one, from 12 to 16 mmol/l in the second, and from 16 mmol/l to the individual maximum – in the third one. 

The test criteria of the “lactate-work power” curve are not applicable to indicate the fifth zone since phosphagen energy sources play the major role in energy supply here. Specific testing procedures defining biochemical parameters are required to determine them. 

It should be emphasized that only dynamic observation during a training macrocycle along with the study of changes in various power zones can be useful in sports practice. With a proper design of the training process a power increase in the aerobic and anaerobic threshold zones is observed in the beginning of the training cycle, but working capacity in the other zones does not change much.

Adjustment of the volume and type of loads based on the systematic study of the lactate curves dynamics is productive for the following reasons. Adjustment of the impact tendency based on the assessment of the lactate curves shape changes allows to choose the load intensity level not by intuition, but in accordance with the adaptive response of the athlete’s body.

Athletes' working capacity in a variety of exercises is largely due to the growth and balance of aerobic and anaerobic functions when performing activities specific for a chosen kind of sport; depending on the nature and conditions of the muscle work performance the athletic performance is defined by a ratio of the following functional properties of the body: alactic anaerobic, glycolytic anaerobic and aerobic capacities. Each of these functional properties can be characterized by three kinds of energy criteria: power, capacity and efficiency. The study of the relationship between changes in the energy indicators and the volume of applied training means of various kinds makes it possible to optimize the training process.  

2. Criteria of athletes’ biochemical adaptation to training loads of various nature in the annual training cycle

Criteria of biochemical adaptation to training loads of various nature are the basis of individual intolerance assessment with regards to training impacts. Their timely analysis makes it possible to avoid straining the muscle work power supply systems. Practical recommendations with regards to biochemical markers assessment are as follows: detection of the CPK activity in the blood serum after power training is recommended for diagnostics of muscle microtraumas or sprains; high CPK activity in athletes at rest provides a basis for a complete diagnostic examination of the muscles condition to identify latent muscle issues caused by increased training loads against the background of prolonged fatigue; urea concentration during training periods and after them reflects adaptive mechanisms associated with protein catabolism; urea concentration analysis is used to assess the body’s reaction to the training loads, the adequacy of the training impacts and the speed of athletes’ recovery.  

Biochemical parameters to a large extent reflect the processes related to the nature and mechanisms of the energy supply of the physical loads, significant changes in the urea level during aerobic exercise are associated with the rate of depletion of carbohydrate energy stores involved in the energy supply of this exercise. Results of the study of CPK dynamics in the blood serum are used for selection of the nature and quantity of exercises for the purpose of an adequate response to the training loads.

3. Assessment of athletes' adaptive responses in the annual training cycle

Differential white blood cell count study is an objective method of assessing adaptive response to training loads. The assessment is based on the analysis of criteria developed for elite athletes.  

The following values of the relative amounts of lymphocytes and neutrophils ratio (in %) in the peripheral blood are recommended when characterizing various types of bodily responses: chronic stress response (less than 26 – over 60); training response (26-32 – 60-55); calm activation response (33-38 – 54-50); increased activation response (39-45 – 49-44); overactivation response (over 45 – less than 44).

When planning an annual training cycle it should be borne in mind that normally the highest values of maximum physical working capacity are observed in male athletes with the increased activation response and in female athletes with the normal training response.

Normal training response is most characteristic for men (35.1%), calm activation response – for women (33.3%). In comparison, the number of increased activation response cases is approximately two times less (16.2% and 17.3% of cases in men and women, respectively). Low incidence of the chronic stress response (12.6% and 14.9% in men and women, respectively) was noted, the lowest frequency rate was recorded for the overactivation response (9.9% and 2.4, respectively), indicating strain in the adaptive mechanisms.  The overactivation response is found in men significantly more often than in women.

A tendency of reduced economical efficiency of performed work was observed in persons with the chronic stress response compared with increased activation response. This is accompanied by significantly higher HR values at different levels of work power and lower working capacity in the glycolytic energy supply zone. Transit to the overactivation response is accompanied by an increase in heart rate at different stages and a later cessation of work in the stress test due to fatigue.       

Elite athletes have various adaptive responses formed under the influence of training loads in order to maintain homeostasis. Formation of supportive non-specific adaptive bodily responses is observed in the majority of subjects (42.3% of men and 50.6% of women). These include calm and increased activation responses. The chronic stress and overactivation responses were observed in 22.5% of men and 17.3% of women. These states are characterized by an increased rate of consumption of substrates providing energy and reduced efficiency of their usage. Experimental data indicate a high efficiency of operation of the energy supply mechanisms during the formation of training, calm activation and increased activation responses.    

This adaptive response is ensured by favorable metabolic background. Athletes with these types of responses have higher values of physical working capacity, and their energy spending rate under the same terms of physical working capacity is lower than in persons with the chronic stress and overactivation responses.

Conclusions:

• Experimental studies reviewed in the article were the basis for development and improvement of practical recommendations on the use of special fitness rating criteria for elite athletes specializing in endurance sports. 
• In the course of adaptation of elite athletes to intense muscular activity it is necessary to take into consideration that the formation of the reactivation and chronic stress reactions may be accompanied by a decrease in physical working capacity. The analysis of these effects makes it possible to optimize the training process by comparing the adaptive bodily response of the athletes with the nature of the training loads performed.  
• Individualization of training programs is required to effectively manage the training process in cyclic sports, with a study of the athletes’ reactions to the impacts of training being its basis. 
• Resistance of the body systems to damaging external influences is regarded as a working capacity criterion. Functional resistance is manifested in the ability to maintain efficient performance for a long time to accomplish training and competitive tasks. This phenomenon is the primary sign of the ability to achieve the best results in sport.

References

1. Volkov N.I., Nesen E.N., Osipenko A.A., Korsun S.N. Biokhimiya myshechnoy deyatelnosti [Biochemistry of muscle activity]. Kiev: Olimpiyskaya literatura publ., 2000, 504 p.
2. Garkavi L.H., Kvakina E.B., Kuzmenko T.S., Shikhlyarova A.I. Antistressornye reaktsii i aktivatsionnaya terapiya. Ch. 1. [Antistress reactions and activation therapy]. Yekaterinburg: Filantrop publ., 2002, 196 p.
3. Rybina I.L., Shirkovets E.A. Osobennosti biokhimicheskoy adaptatsii k nagruzkam razlichnoy napravlennosti biatlonistov vysokoy kvalifikatsii [Features of elite biathletes' biochemical adaptation to stress of various nature]. Vestnik sportivnoy nauki, 2015, no. 3, pp. 28-33.
4. Brancaccio P, Lippi G, Maffulli N. Biochemical markers of muscular damage. Clin Chem Lab Med, 2010, no. 48(6), pp. 757-67.
5. Iashvili G., Chkhikvishvili M., Kobelashvili D. Indices of immune reactivity of sportsmen organism after one time physical load of different intensity and duration. Georgian Med. News, 2010, no. 179, pp. 30-33.

Corresponding author: eshirkovets@yandex.ru

Abstract

Innovative aspect of the study is due to the system approach to the analyses of bio-energetic, ergometric and biochemical markers of the elite athletes’ special working capacity in endurance sports. Having analyzed the special fitness criteria, we found that an efficient training process management system is to be based on due assessments of variable parameters to rate physical loads and their impacts versus the adaptive capabilities of the athletes.