He medalled four times at the World Championships, winning gold in 1995, and competed at the 1992 and 2000 Olympics as a welterweight (-74 and -76 kg), finishing in 5th and 15th place, respectively.

[1] At the 1989 World Espoir (under-20) Championships in Budapest, Riemer won his first international gold in the Greco-Roman -74 kg category.

He barely missed the podium at the World Championships, losing to Cuban Filiberto Azcuy by points in a fight for bronze.

[3] His last major success was a silver medal at the 1999 World Championships in Athens, where he lost 11:0 in 2 minutes and 41 seconds to Nazmi Avluca in the finals.

[5] Riemer is married to Sophie Pluquet, who also won a gold medal at the 1995 World Wrestling Championships in women's freestyle (-53 kg).