TY JOUR TI Interval training method for developing special endurance in orienteering athletes aged 13 to 16 years KW sport orienteering KW youth sports KW interval training KW rugged terrain KW sandy surface KW specific endurance JO Scientific notes of P. F. Lesgaft University AU Yakovenko, D.V. AU Efimova, E.V. AU Mikhailova, S.N. PY 2025 IS 0 PB National State University of Physical Education, Sports and Health named after P.F. Lesgaft