TY JOUR TI CONDITIONS FOR THE DEVELOPMENT OF STRONG-WILLED QUALITIES OF ADOLESCENTS THAT CONTRIBUTE TO ACHIEVING SPORTING SUCCESS KW strong-willed qualities KW motivation KW adolescence KW sports environment KW sports success JO Scientific notes of P. F. Lesgaft University AU Karyakin, R.E. PY 2023 IS 0 PB National State University of Physical Education, Sports and Health named after P.F. Lesgaft