Dobeleit was born in Renchen, Baden-Württemberg. At the 1987 World Championships he placed fifth in 4 x 100 metres relay and fourth in 4x400 metres relay. At the 1988 Summer Olympics held in Seoul, South Korea he helped win the 4 x 400 metres relay bronze medal with his teammates Edgar Itt, Jörg Vaihinger and Ralf Lübke.