Oelsner was born on 19 June 1970 and is currently an advertising salesman. In 1991 he was injured in a motorcycle accident which left him with a paralysed left arm. He entered the 1994 Winter Paralympics in Lillehammer as a LW6 class competitor in the biathlon and cross country skiing. Oelsner's first games were a success, winning three golds, one solo silver, and one silver as part of the German relay team. Since then he has continued to use the same skis, even sleeping with them, as a matter of tradition. At the 1998 Games in Nagano he won two golds and one individual silver, and a silver with the German relay team.