[1] Muff first began riding on his father's cavalry horse and became interested in show jumping at an early age.

Between 1994 and 1996, his employer was Thomas Fuchs in Bietenholz, and from 1996 to 2000, he worked for Manfred Birchler in Bilten.

There he won his first Grand Prix on the horse BB Cardinale and received the opportunity to ride Nation's Prices.

He competed in the 2012 Summer Olympics, earning thirty-third individually and being part of the fourth-place Swiss team.

In 2010, Muff won the equestrian Swiss Cup final in Ascona for the third time.