TY JOUR TI METHODOLOGICALFEATURES OF LONG JUMPERS PREPARATION AT THE STAGE OF INITIAL SPECIALIZATION KW young athletes KW long jump KW training methodology KW jumping exercises KW training stages KW initial specialization JO Scientific notes of P. F. Lesgaft University AU Tihonov, Y.V. AU Kryazhev, V.D. AU Marinina, N.N. AU Grunina, I.V. PY 2023 IS 0 PB National State University of Physical Education, Sports and Health named after P.F. Lesgaft