He won the gold medal in the decathlon in the 1988 Summer Olympics, held in Seoul, South Korea.

He missed the 1992 Summer Olympics in Barcelona because of an injury and came fourth in the 1993 World Championships in Athletics in Stuttgart.

This ranks him ninth among German decathletes, behind Jürgen Hingsen, Uwe Freimuth, Siegfried Wentz, Frank Busemann, Torsten Voss, Guido Kratschmer, Paul Meier and Siegfried Stark.

[1] Schenk cleared 2.27 m (7 ft 5+1⁄4 in) in the 1988 Seoul Olympics to share the World Decathlon Best in high jump with Rolf Beilschmidt, until the Canadian Olympic high jump gold medalist Derek Drouin improved the record by 1 centimeter in an decathlon competition in 2017.

[2] Schenk was noted for his use of the old-fashioned straddle technique, at a time when the Fosbury flop had become almost universal in competitive high jumping.