TY JOUR TI METHODS OF DEVELOPING LEG FLEXIBILITY AT THE TRAINING STAGE OF FITNESS IN TAEKWONDO KW taekwondo KW methods KW flexibility KW training stage JO Scientific notes of P. F. Lesgaft University AU Malyshkin, D.V. AU Chuchkov, V.M. AU Sergeev, V.G. PY 2023 IS 0 PB National State University of Physical Education, Sports and Health named after P.F. Lesgaft