Martínez broke the Cuban record for the long jump eleven times, resulting in a lifetime best of . She was a gold medallist in the long jump at the 1966 Central American and Caribbean Games and was the inaugural champion at the 1967 Central American and Caribbean Championships in Athletics. She also enjoyed success in the 4 × 100 metres relay, winning medals at the 1963 Pan American Games, 1963 Summer Universiade and the 1966 CAC Games, as well as twice breaking the national record for the event.