Try downhill mountain bike with a guide.

2 options  :

1) Pure DH using the lift up

1/2 day with advices of the instructor (allows going downhill 2 times)

Included : Bike rental with protection. The instructor.

Not-included : Lift pass . See the prices on tourist office site

Price : 85€

2) Easy downhill tracks from Sixt 

2 h easy downhill from Sixt Fer à Cheval to Samoëns

ALL INCLUDED: Bike rental, helmet. Instructor. Shuttle bus up to Sixt.

Price: 35€