Competing in two Winter Olympics, he won the silver medal in the men's singles event at Innsbruck in 1976.

Fendt also won two gold medals in the men's singles event at the FIL World Luge Championships, earning them in 1970 and 1974.

Additionally, he won a silver medal in the men's singles event at the 1973 FIL European Luge Championships in Königssee, West Germany.

Fendt's sister, Andrea, won the silver medal in the women's singles event at the 1978 FIL World Luge Championships in Imst, Austria.

On Fendt's 61st birthday in Munich, he received the Bundesverdienstkreuz Verdienstkreuz am Bande (Cross of the Order of Merit of the Federal Republic of Germany) for his contributions toward society, mainly in luge.