V.A. Vishnevsky, professor, Ph.D.
A.A. Monastyrev
K.A. Mironova
Surgut State University, Surgut

Key words: cold test, physical loads, mechanisms of reaction.

Relevance. As a result of stress, unhealthy environment, bad habits, rage over medicine the immune system of people has been experiencing a huge load in recent years. Non-compensated strain of the immunity puts the body in a border state that can turn into a disease. The most common ones are catarrhal and contagious diseases. In the preschool and primary school years they account for up to 62.7% of frequent diseases in children [3].

Cold-tempering activities and physical exercises are the common ways to strengthen the immune system. However, the use of these ways is associated with a number of organizational difficulties. For exercises it is determination of the optimal volume and intensity of loads, as a positive cross effect is promoted only by the load of health-improving physical culture. Overloads in elite sport cause immunosuppression (the negative cross effect).

There are some organizational problems with cold tempering. Scientific «gentle» methods of cold tempering provide treatments of gradually increasing intensity and duration of exposure. However, if evolutionary formed mechanisms of urgent adaptation are capable of coping with the current stimulus, no tempering will take place. In order to activate the mechanisms of long-term adaptation, the force of the stimulus should be slightly higher than the existing capacity. It is an energy deficit resulting from the failure of urgent adaptation that eventually forms the «structural trace» that underlies the increase in the body’s resistance to a variety of adverse factors.

The main difficulty of «tough» methods of tempering is that under extreme conditions the human body is unable to simultaneously show the maximum of all its functions. Therefore, strong stimuli provoke intensification of some functional systems accompanied by inhibition of others. That is why numerous facts of negative results of the suboptimal adaptation to hypoxia, cold, physical loads, expressed in reducing of organs’ weight characteristics, reduction of cells in the liver, kidneys, etc. are presented in the literature [2].

It makes researchers and practitioners seek ways to optimize the process of control of hardening [1]. We took interest in the opportunity of using a cold test for this purpose, which was the subject of this study.

Organization of the study. The study involved 19 students aged 19-20 years. The cold test was our modified version of the test of M.Ya. Marshak. An aluminum cylinder of diameter 20 mm and wall thickness 1 mm, filled with ice was used as the cold stimulus. After preliminary measurement of the temperature of the upper third of the lateral surface of the forearm the cylinder filled with ice was applied to it for 30 seconds. After the termination of the cold stimulus action temperature of the cooled part of the arm was measured till its full recovery. The test was held at rest, after a 20-minute cycle ergometer exercise and after a 20-minute weight exercise with dumbbells for arm and upper body muscles. The temperature was recorded with a thermocouple using a hardware-software complex «Navigator» for training with biofeedback. Before the cold test heart rhythmograms of all the subjects were recorded using a hardware-software complex «OrthoSport». The complex is used to evaluate adaptability of the body, stress level of regulation systems, functional reserves of the body, autonomic support of functions, initial autonomic tone. 

Study results. Table 1 presents the results of studying the reference temperature, the lowest at the time of action of the cold stimulus and the recovery temperature 5.5 minutes later. They show that after the cycle ergometer exercise the temperature of the forearm significantly decreases, probably due to redistribution of blood to the lower extremities and a spasm of capillary tubes in the upper parts of the body. On the contrary, after weight training the skin temperature of the upper part of the body increased due to a rush of warm blood.

Table 1. Temperature change of the lateral surface of the forearm under different cold test conditions, М ± σ (n = 19)

* - the changes are significant compared to the temperature at rest when p < 0.05

The test conditions did not significantly affect the degree of the temperature drop. As for the recovery temperature, its significant excess compared to the temperature at rest was detected only after weight exercises (Table 1).

Temperature recovery rate in the cold test is especially informative. It not only describes the reactivity of the organism to the test, but also reflects the effectiveness of tempering treatments. The fact is that the temperature recovery rate always increases in case of the rationally conducted tempering, regardless of the reference values, reflecting the positive impact of adaptive changes in response to tempering. The results of changes in the temperature drop and recovery rates at various stages of the test are presented in Table 2.

Table 2. Dynamics of changes in the rate of decrease (increase) of temperature of the forearm at different stages and under different conditions of the cold test, М ± σ (n = 19)

* – the changes are significant compared to the rate at rest when p < 0.05

^ – the changes are significant compared to the previous study when p < 0.05.

Its analysis shows that two phases can be defined in the temperature recovery after the exposure to cold - those of fast and slow recovery. After physical exercises these phases smoothly run into one another, while at rest some delay is marked in the temperature recovery between the 2nd and the 3rd minutes. The second identified feature is that the fundamental difference in the temperature recovery rate under various conditions of the test is observed only in the phase of its fast recovery. It is significantly higher after weight training compared to the state of rest. There is just a tendency of the rate increase after the cycle ergometer exercise, but it does not reach any significant values. 

This is also evidenced by the correlation analysis. For example, while the speed during the 1st minute of recovery during the test at rest significantly correlates with the recovery rate during the 1^st (r = 0.730, p < 0.01), 2^nd (r = 0.626, p < 0.01) and 3^rd minutes (r = 0.509, p < 0.05) after the cycle ergometer exercise, the test held after weight training revealed such an association only for the 3^rd minute of recovery (r = 0.550, p < 0.01).

Various physiological mechanisms are the basis of the identified features of the body’s response to the cold test. The second (slow) phase of temperature recovery has a single mechanism, regardless of the test conditions. Thus, better adaptability of the body promotes higher temperature recovery rate from the 4th to the 5th minute (at rest r = 0.628, p < 0.01, after cycle ergometer exercise r = 0.433, p < 0.05, after weight training r = 0.496, p < 0.05). And it is higher when the level of the regulatory stress of cardiac activity is lower (at rest r = -0.571, p < 0.01, after cycle ergometer exercise r = -0.455, p < 0.05, after weight training r = -0.464, p < 0.05). Finally, more adequate autonomic support of the body promotes higher temperature recovery rate (at rest r = 0.483, p < 0.05, after cycle ergometer exercise r = 0.518, p < 0.05, after weight training r = 0.451, p < 0.05).

The rate in the phase of fast temperature recovery at rest is directly proportional to the activity of the sympathetic nervous system responsible for adaptation (LF: r = 0.504, p < 0.05; stress index r = 0.491, p < 0.05; HR r = 0.518, p < 0.05), and is inversely proportional to the activity of the parasympathetic division (variation range: r = -0.494, p < 0.05). There were not revealed any significant relationship of the rate in the phase of fast temperature recovery after the cycle ergometer exercise with the autonomic support of the functions and the level of neurohumoral regulation. After weight training this parameter significantly correlates with the general level of neurohumoral regulation (r = 0.432, p < 0.05) and the sympathetic activity (LF: r = 0.574, p < 0.01).

The resting rate of temperature decrease influenced by the cold stimulus is significantly related only with the index of the orthostatic test (r = 0.433, p < 0.05). Such associations were not detected after the cycle ergometer exercise, while after weight training it is directly proportional to the stress level of the mechanisms of neurohumoral regulation (r = 0.552, p < 0.01), inadequate adaptation (r = 0.494, p < 0.05) and the level of functional reserves’ decrease (r = 0.455, p < 0.05).

The regularities identified in the body's response to the cold test, conducted in different ways, help optimize the selection of options for tempering procedures depending on the initial state of the body, to assess its effectiveness, take into account the mutual influence of the combination of hardening and multi-purpose exercises.

References

1. Vishnevsky, V.A. System analysis of the body status of schoolchildren at the stages of ontogenesis / V.A. Vishnevsky, V.V. Apokin, D.V. Serdyukov et al. – Moscow: Teoriya i praktika fizicheskoy kultury i sporta, 2010. – 367 P. (In Russian)
2. Praznikov, V.P. Hardening of preschoolers / V.P. Praznikov. - Leningrad: Meditsina, 1988. – 224 P. (In Russian)
3. Rumyantsev, A.G. Weak children / A.G. Rumyantsev, V.N. Kasatkin // Shkola zdorov'ya. – 1996. – V. 3. – № 2. – P. 41–47. (In Russian)

Corresponding author: apokin_vv@mail.ru