In athletics, Lundemo won ten national titles in Norway. He won the 10,000 metres title in 1961 and 1962, the marathon title in 1964, the 25 kilometres road race in 1961, 1962, 1963 and 1964, the 8 kilometres cross-country race in 1960, the cross-country single start race in 1961 and 1962. In the 10,000 metres, the 8 kilometres cross-country and the cross-country single start he also won silver and bronze medals, the last time in 1968. He competed once in an international event, when he finished nineteenth in the 10,000 metres event at the 1962 European Championships.