Associate professor, PhD A.A. Kuzhuget
Associate professor, PhD G.N. Kazakova
Associate professor, PhD T.V. Kolpakova
Associate professor L.G. NosovaKrasnoyarsk State Pedagogical University n.a. Astafiev, KrasnoyarskKrasnoyarsk State Medical University n.a. professor V.F. Voyno-Yasenetsky, Krasnoyarsk

Keywords: student-athletes, sports, rheovasography, regional blood flow.

It is known that regular exercise considerably affects the peripheral circulation, thus leading to an increase in the oxygen and energy supply of the working muscles [1; 6]. The adaptive response is aimed at vasoconstriction in the non-working areas and increased blood flow in the working ones [4].

Among the indirect methods of studying the circulation is rheography. Rheography is a method used to register changes in the electrical resistance of tissues when electric current passes through them, which enables to estimate blood filling in vessels [2; 3; 5; 7; 8].

The study of blood flow in the lower extremities is of particular interest as they ensure body motion when performing training loads.

Objective of the research was to study regional blood flow characteristics in students engaged in different sports.

Methods and organisation of the research. For the purpose of the study we examined male athletes aged 18-23 years. Depending on their sports activities, all subjects were divided into four groups. Young males involved in athletics (AL, 32 people), powerlifting (PL, 35 people), judo (JD, 48 pers.) and practically healthy students attending physical education classes under the program for the basic health group (BHG, 40 people).

According to the sport skill level athletes were split into low skilled (LS) and elite (E) athletes. The LS group included males from beginners to 2nd class athletes, and the elite group - 1st class athletes, candidates for and masters of sports.

Blood circulation in the lower extremities was estimated by means of rheovasography using the "Valenta+" diagnostic complex produced by LLC SPE "NEO", Saint Petersburg, Russia.
The following indicators were evaluated:

1. Arterial blood flow intensity indicators - systolic wave amplitude (SWA, Ohm), rheographic index (RI, c.u.);

2. Vascular tone and elasticity indicators - rapid blood filling time (RBFT, sec) and slow blood filling time (SBFT, sec); elasticity coefficient (EC, %); pulse transit time (from the ostium aortae to the area under study) - PTT, sec;

3. Venous return indicators - venous ratio (VR, %) and venous outflow coefficient (VOC, %).

Since there are no statistically significant differences between the indices of the right and left extremities, this paper presents the data retrieved from the "right shin" segment.

The statistical processing of the research data was made on a personal computer using SPSS for Windows v13.0.

Results and discussion. Most resting indices in LS athletes and students of BHG differed, which indicates the optimized regional blood flow in beginners compared with non-athletes. Thus, PTT, RI, and SWA in athletes were higher by 7.9-24.5%, while EC - lower by 10.2% less; moreover, the PTT values differed statistically significantly (p<0.05). These differences were even more significant after exercise. Low-skilled athletes had higher arterial flow and lower vascular resistance to blood flow, as evidenced by the higher values ​​of RI, SWA, and PTT and lower values of EC (p<0.05). This proves that regional blood flow improves at the early stages of aerobic training.

Skilled athletes differed from low-skilled ones by higher values ​​of PTT, lower tone of the large-bore arterial vessels, as evidenced by the lower values of RBFT (p<0.05). There were no significant differences in LBFT and EC between elite and low-skilled athletes.

Elite athletes were observed to have higher values ​​of RI and SWA compared with low skilled athletes (p<0.05), which testified to greater blood supply. More intense arterial flow in elite athletes was accompanied by improved venous return. Herewith, the VR and VOC values in elite athletes were lower by 10.6 and 5.3% than in low-skilled ones.

After the exercise, no significant differences in PTT, RBFT, SBFT were identified between elite and low-skilled athletes. However, the elasticity coefficient in elite males was lower by 2.1% (p<0.05), while RI and SWA - higher by 18.4% and 18.6% (p<0.05) compared with low-skilled athletes, which indicates a decrease in the resistance to blood flow and an increase in the intensity of blood supply of the area under study in more skilled athletes. As in the state of relative rest, this was accompanied by better venous outflow.

Comparative analysis of elite and low-skilled powerlifters revealed that sport skills excelling process was not accompanied by any positive changes in blood supply.

If you compare low-skilled judokas and students from BMG at rest, you will see that these groups have no significant differences.

At the same time, when comparing low-skilled and elite judokas, we established that their sport skills improvement was accompanied by an increase in venous outflow (VR was lower by 7.7% compared with low-skilled judokas).

No significant differences were observed in most rheovasographic indicators between judokas of different skill levels after standard exercise.

Consequently, elite judokas have lower tone of arterial vessels of different bores and higher blood filling with improved venous return as compared to low-skilled athletes. Apparently, this situation is due to the peculiarities of judo, where, along with the preferential development of athlete's speed-strength abilities, their overall endurance is developed, too.

Table 1. Rheovasographic indices in elite athletes (M±m)

Note: Statistically significant differences in the mean values were determined using ANOVA for non-parametric independent samples with respect: ° - to AL; * - to PL (p<0.05).

According to rheovasography (Table 1), when at rest, athletes and judokas had higher PTT, RI, and SWA, and lower EC, SBFT as compared to powerlifters, besides in some cases, the differences were statistically significant (p<0.05). This may indicate the optimization of regional blood flow in athletes and powerlifters under the influence of sport training. More significant differences between the groups of elite athletes were identified after exercise (Table 1), i.e. judokas and athletes differed from powerlifters by lower vascular tone and intensity of regional blood flow. In addition, athletes and judokas were characterized by better venous outflow, as indicated by lower values ​​of venous ratio compared with powerlifters (p<0.05). At the same time, it was athletes, rather than judokas, who had more differences in all the studied indicators compared with powerlifters, which was apparently caused by a high degree of aerobic exercise in the training process.

Conclusion. It was found that elite athletes and judokas have higher blood filling in the lower extremities and improved venous outflow at rest and after exercise as compared to unskilled athletes, powerlifters and students of the basic health group. We assume that a significant difference between the indices in athletes and judokas is due to the aerobic exercises dominating in the training process as compared to the rest of the examined groups.

References

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Corresponding author: kartysh84@mail.ru

Abstract

Objective of the research was to study regional blood flow characteristics in students engaged in different sports.

Students of the basic health group and those engaged in athletics, powerlifting and judo sport sections were examined in the study. Indicators of regional muscle blood filling were compared in view of sport skill level and duration of studies in the university. It was found that elite athletes and judokas have higher regional blood filling indices and improved venous drainage at rest and during exercise as compared to unskilled athletes, powerlifters and students of the basic health group.