CC BY
10REACTION OF LOWER LIMB REGIONAL BLOOD FLOW TO STEP ERGOMETER
LOAD IN ATHLETES
A.V. Kabachkova, Ph.D.
Yu.S. Frolova, postgraduate student
L.V. Kapilevich, professor, Dr.Med.
National Research Tomsk State University, Tomsk
Key words: regional circulation, blood filling, sport games, martial arts.
Introduction. Adaptation to muscular activity is a systemic response of the body, aimed at achieving a high fitness level with the minimal physiological cost [3]. This dynamic process is based on the formation of a new response program, which is determined by external and internal conditions of activity. Cardiovascular system (CVS) acts as one of the limiting factors, the realization of the motor potential depends on its adaptabilities. Numerous scientific papers, particularly in the field of cardiodynamics and systemic hemodynamics, are dedicated to the studies of athletes' cardiovascular system [1]. It is still relevant to study the features of regional circulation. Currently, reports on the state of the muscle blood flow in athletes engaged in cyclic (athletics, swimming, skiing, cycling, short track) and acyclic, mainly power, sports (weightlifting, powerlifting) are available [2, 4]. Rheovasography is among the methods for studying the peripheral circulation.
The purpose of the study was to examine the response of the lower limb regional blood flow to the step ergometer load in athletes depending on the type of training process.
Materials and methods. The study involved 60 men of 18-20 years old. Two experimental groups consisted of 20 athletes engaged in sport games and 20 engaged in martial arts. All the surveyed had sports categories of at least Ist senior. The control group consisted of 20 students (of major medical group) attending physical education classes twice a week.
A rheographic study of lower limbs was carried out using the hardware-software complex «Valenta» (LLC «Company Neo», Russia). The indices were recorded in a state of relative rest (baseline record) and after a standard step ergometer load (functional test). Before the study blood pressure and pulse were measured (heart rate higher than 90 bpm served as a contraindication to the study). When performing the functional test step ergometer load was used
in the form of climbing up a step (50 cm high). The movements pace - 30 movements per minute - the metronome was set at 120 bpm. The time frame of the test - 5 minutes.
The data were statistically processed using the STATISTICA 8.0 software program that includes calculation of descriptive sample parameters, the Shapiro-Wilk normality test and comparative analysis of the dependent (t-test for dependent samples, Wilcoxon matched pairs test) and independent samples (t-test for independent samples, Mann-Whitney test). p<0,05 was taken as a statistically significant difference.
Results and discussion. All rheovasography results were combined into four groups that characterize peripheral circulation: blood filling indicators, characteristics of the outflow and inflow of blood, outflow-to-inflow ratio (Figure 1). Rheographic indicators registered in the «right thigh» segment were used for the analysis and interpretation (all subjects had a leading right leg).
Rheographic indicators of blood filling in the test samples are within the physiological norm. In all the observed groups the blood filling indicators after the step ergometer load increased (p<0.05) or have a upward tendency (p>0.05), such a reaction is adequate for the load imposed. According to J.P. Clausen et al. (1973), in the process of working peripheral vascular resistance reduces by 4-5 times compared with the state of rest, that leading to an increase in blood flow in the working muscles by 10-20 times. The relative volume pulse in the studied segment in a state of relative rest does not differ significantly in either of the observed groups, but higher average sample indicators were registered in the «Martial Arts» group - 0.83±0.27%o («Sport Games» had the average of 0.72%; «Body Conditioning (BC)» - 0.69%). The postexercise pulse blood volume in the «Sport Games» group increased statistically significantly (by 50%). In the OPC and «Martial Arts» groups the increase was insignificant - 13 and 4%, respectively. Amplitude data, rheographic index (RI) and amplitude-frequency characteristic (AFC) in the state of relative rest do not differ in either of the observed individuals, but a statistically significant increase of these indicators was registered with the «Sport Games» athletes after the exercise. A significant increase (by 23%) of the amplitude of the arterial component maximum was registered in this group, while in the BC and «Martial Arts» groups this indicator increased by 14 and 11%, respectively. RI and AFC values did not change significantly in these groups, while an increase of RI by 19% and AFC by 28% were registered in the «Sport Games» group.
Blood inflow characteristics. Time and speed parameters of vessels filling reflect the tone of the peripheral arteries of various calibers. Judging by the rapid and slow blood filling time ratio, the tone of small arteries prevails in all the subjects in the state of relative rest. Integral tone of the arterial bed vessels is higher in the athletes of both groups compared to the control group (BC). For example, the elasticity modulus in the BC group is within the normative range of 11-15%, while the average sample values of this parameter in the «Sport Games» and «Martial Arts» groups exceed it - 18 and 17,5%, respectively. After performing the step ergometer load the tone of the arteries of medium and small caliber did not change statistically significantly in either of the groups. At the same time the large-caliber arterial tone increased in the «Sport Games» group by 11% and did not change in the «Martial Arts» and BC groups.
Blood outflow characteristics. Indicators of venous outflow in the state of relative rest corresponded to average norms (no significant differences in the organization of venous outflow were detected). After performing the step ergometer load the venous outflow increased by 1.4 in the BC group, by 3.2 in the «Martial Arts» group, and did not change in the «Sport Games» group.
Blood outflow-to-inflow ratio. Pre- and post-capillary peripheral vascular resistance reflects dicrotic and diastolic indicators, respectively. These indicators correspond to guideline values and do not change statistically significantly while performing the standard load in the BC group. A significant increase of these indicators is recorded in the «Sport Games» group, but within the normal range of values. Low pre- and post-capillary peripheral resistance is recorded in the athletes of the «Martial Arts» group. The pre-capillary tone increases, and the postcapillary one decreases in response to step ergometer load.
Conclusion. The reaction of the lower limb regional blood flow to the step ergometer load varies in athletes depending on the nature of the training process (Figure 1). For those engaged in sport games an increase of blood filling of the vessels of the thigh is characteristic as well as an increase of the tone of the large caliber arteries at the constant level of venous outflow, and an increase of peripheral vascular resistance at the pre- and post-capillary levels. This group was characterized by a high level of venous outflow in the state of relative rest. Athletes involved in martial arts demonstrated a reaction of the regional blood flow that was in many ways the opposite: blood filling of the peripheral vessels did not change significantly in response to the load (a high level of blood filling in the state of relative rest was registered in this group), the
tone of large caliber arteries remained unchanged. The decreased pre- and post-capillary peripheral resistance was registered after the load (by the increased tone of pre-capillaries and its decrease at the post-capillary level), that leading to increased venous outflow. Sport games and martial arts are situational sports requiring a complex manifestation of physical qualities and motor skills in variable modes of motor activity, continuous changes of situations and forms of action. However, the ratio of static and dynamic loads in the training process of athletes is different. Apparently, the prevalence of dynamic loads in the training structure of athletes involved in sport games predetermines high «readiness» of blood filling of lower limb regional vessels for a rapid response to a load and a high level venous outflow even in the state of rest. In the group of athletes involved in martial arts, the amount of static loads (especially for the lower limb muscles) is higher, which leads to high blood filling in the state of relative rest and the venous outflow enhancement in response to the load through the tone redistribution between the pre-and post-capillary sphincters.
References
1. Ivanova, N.V. Factors determining the functional state of the cardiorespiratory system of cyclic athletes // Slobozhanskiy naukovo-sportivny visnik, 2013. - № 5 (38). - P. 108-111. (In Russian)
2. Kir'yanova, M.A. Rheographic indicators of cyclic athletes / M.A. Kir'yanova, I.N. Kalinina, L.G. Kharitonova // Vestnik YuUrGU. - 2010. - № 24. - P. 125-128. (In Russian)
3. Kostyunina, L.I. The features of adaptation of athletes to training loads // Pedagogiko-psikhologicheskie problemy fizicheskoy kul'tury i sporta. - 2011. - № 4 (21). - P. 55-60. (In Russian)
4. Kudrya, O.N. The features of peripheral hemodynamics of athletes during adaptation to loads of different orientation / O.N. Kudrya, M.A. Kir'yanov, L.V. Kapilevich // Bulleten' Sibirskoy Meditisiny. - 2012. - № 3. - P. 48-52. (In Russian)
5. Ogurtsova, M.B. Comparative typological characteristics of the central circulation and physical working capacity of swimmers and runners / M.B. Ogurtsova, A.N. Demin, T.V. Mel'nik // Fizicheskoe vospitanie studentov. - 2009. - № 1. - P. 39-41. (In Russian)
6. The state of regional circulation of elite athletes / E.Yu. Drattsev [et al.] // Vestnik sportivnoy nauki. - 2008. - № 3. - P. 32-35. (In Russian)
Figure 1. Functional profile of the reaction oof lower limb regional blood flow («right thigh» segment) to step ergometric load in athletes.
Note. Change of indicators after the step ergometer load is presented in conventional units, the data of the BC group is taken as a conventional unit (scale division is 1 conventional unit, the minimum of axis - 2 conventional units, the maximum of axis - 6 conventional units).
1 - relative volume pulse; 2 - rheographic index; 3 - amplitude-frequency component; 4 -maximum of arterial component; 5 - elasticity modulus; 6 - average speed of rapid filling; 7 -venous outflow; 8 - dicrotic index; 9 - diastolic index.
1-4 - blood filling; 5, 6 - blood inflow; 7 - blood outflow; 8, 9 - blood outflow-to-inflow ratio.
* - Data in the observed groups «Sport Games» and «Martial Arts» are reduced by 10 times. Corresponding author: [email protected]
