TY JOUR TI Organization of sports training for qualified long jumpers using blood enzyme activity KW athletics KW long jump KW sports biochemistry KW creatine kinase KW individualization of the training process KW blood biomarkers JO Scientific notes of P. F. Lesgaft University AU Grivtsov, L.K. AU Sukhareva, S.M. PY 2025 IS 0 PB National State University of Physical Education, Sports and Health named after P.F. Lesgaft