Mezue ahịrịokwu na-esonụ: Diener meriri asọmpi mba ụwa mbụ ya na European Junior Championships 2010 na 50m backstroke. Otu afọ mgbe e mesịrị, na 2011, ọ gbachitere ọla edo ya ma merie na 100m na 200m azụ na European Junior Championships na Belgrade (Serbia) wee merie ọla edo na World Junior Championships na Lima (Peru) na 50m azụ. Christian Diener meriri ọlaọcha na 50m backstroke na European Short Course Swimming Championships 2013 na
2014 na European Aquatics Championship. Ọ bụ onye otu ndị otu egwuregwu German na 2016 Summer Olympics na Rio de Janeiro ma sonye na 200m backstroke, na-agwụ 7th.