In 1999, Baumann tested positive for the performance-enhancing drug nandrolone and received a two-year suspension from athletic competition.

Born in Blaustein, West Germany, Baumann was one of the few non-African athletes who were able to seriously challenge the African dominance of middle-distance running during the 1990s.

Baumann missed most of the 1990 season due to tendon trouble, but he returned in 1991 to finish fourth in the 5,000 m at the World Championships in Tokyo.

At the Olympics in Barcelona, the 5000 m final started at a fast pace, but then slowed, increasing Baumann's advantage due to his finishing kick.

At the World Championships in Gothenburg, in the 5,000 m final, Baumann inexplicably lost contact with the leading group with three laps to go, and struggled home in a disappointing ninth place.

However, a few days after the disappointment of Gothenburg, Baumann ran one of the fastest races in his career when he broke his national record (13:01.72) to come second in Zürich behind Haile Gebrselassie.

On 19 October 1999, Baumann tested positive for nandrolone and received a two-year suspension, thus missing the 2000 Summer Olympics.

Those defending Baumann have pointed to the fact that the levels of nandrolone found in his body were completely abnormal for any athlete wishing to enhance his performance.