He won the gold medal in the men's singles event at the 1962 FIL European Luge championships in Weissenbach, Austria.

He was selected for the men's singles event at the 1964 Winter Olympics, but was severely injured at the luge track in Igls and did not compete as a result.

Lenz later became a luge coach, being involved in the early career of Austria's Markus Prock.

[4] In December 1993, Lenz lost his left leg below the knee when he did not get out of the way of an American luger while clearing off the ice at the bobsleigh, luge, and skeleton track in Winterberg, Germany.

Lenz returned to coach the German team at the 1994 Winter Olympics in Lillehammer two months later.