I.Kh, Vakhitov
professor, Dr.Biol.
A.A. Gaynullin, E.G. Kabysh
Institute of physical culture, sport and rehabilitation medicine of Kazan Volga region federal university, Kazan

Key words: stroke volume, skydivers, athletes of different qualifications.
Recently skydiving has become a very popular sport in Russia and the Republic of Tatarstan. Quite many young people are doing it. Herewith, skydiving makes specific demands to the involved ones. Skydivers are usually nit subject to strenuous muscular loadings, but when gettign ready for a jump and landing substantial changes take place in their body. A skydiver is to have special psychological abilities. Skydiving has its specifics and is distinguished by the effect of stress factor on a skydiver's body during a jump. The researchers assume that long-term occupations of this sport provoke significant changes in the functioning of various organs and systems. But the peculiarities of changes of the indices of heart pumping function of the growing body at regular skydiving occupations are still understudied.
The purpose of the study was to study the stroke volume indices of young people involved in skydiving on a regular basis.
The risk of performance of exercises increased with the rise of complexity of skydives. The negative reaction of stroke volume, detected in beginning skydivers and ex-master of sport after a skydive is assumed to be due to high heart rate indices, which can be the reason of decrease of the diastolic pause of heart, provoking the decrease of ventricular blood filling, resulting in the drop of skydivers' stroke volume.

References

1. Vakhitov, I.Kh. The features of heart rate changes in athletes engaged in skydiving on a regular basis // Proceedings of the All-Rus. scient. conf. with internat. participation "Acute researchesin the field of physical culture science" / I.Kh. Vakhitov. – Kazan, 2010. (In Russian)
2. Gavrilina, A.V. The influence of emotional stress on accuracy of teaching time in an extreme situation // Proceedings of the scientific student conf. of the university "Dubna" / A.V. Gavrilina. – Dubna, 2006. – P. 27-30. (In Russian)
3. Kubicek, W.G., Kamegis, J.W., Patterson, R.P., Witsoe, D.A., Mattson, R.H. Development and evaluation of an impedance cardiac output system. Aerospace Med 1966, 37:1208-12.