Born in Stolin, she was initially interested in basketball but the lack of a local team left her unable to pursue the sport further. Astapchuk instead entered throwing events and her first international title came at the age of seventeen, as she won the shot put at the 1998 World Junior Championships in Athletics. She was dominant at the younger levels and won at the 1999 European Athletics Junior Championships and then the 2001 European Athletics U23 Championships.