TY JOUR TI Means of developing strength and speed-strength abilities in middle-distance runners to improve the elements of "active running" KW athletics KW middle distance running KW active running KW tempo-rhythmic structure KW flight phases KW step frequency KW training JO Scientific notes of P. F. Lesgaft University AU Bashkina-Gabruskaya, A.V. PY 2025 IS 0 PB National State University of Physical Education, Sports and Health named after P.F. Lesgaft