A St. Jago High School teammate of Yohan Blake, Ashmeade first enjoyed success in the sprints as a junior athlete: at the 2006 Central American and Caribbean Junior Championships he beat compatriot Dexter Lee to the 100 m title, was runner-up to Ramone McKenzie over 200 m, and teamed up with the pair to bring Jamaica the 4×100 meter relay title. Another medal haul came for the young Jamaican at the 2007 World Youth Championships in Athletics, where he was second to Lee in the 100 m, ran a 200 m best of 20.76 seconds for the bronze medal, and helped the national team to another bronze in the sprint medley relay. He competed at the Penn Relays in 2008 and represented his school, St. Jago High School – an institution renowned for producing track and field athletes.