1. Uphill Skiing: Hiking uphill puts you out in nature, which is good for your head, and gets you building your quadriceps, lungs and hammies all at the same time.

2. Snowball Biathlon (cross-country skiing with snowball fighting): Cross-country skiing is a one-of-a-kind fat-burner. When combined with snowball fighting--a combination of bending, stacking, throwing and running ­it gives you a fierce workout.

3. Synchronized Greco-Roman Wrestling: Grab a friend, your kid or your wife and grapple Greco-style. It is a great workout for your shoulders, arms and back.

4. Giant Slalom Tobogganing: Must be done without the ski lift. It's the climbing up the hill carrying your sleigh that's good for your back, biceps, shoulders and legs, not the going down part. Avoid trees or be penalized.

5. Polar Bear Club: Nothing beats swimming for great abs. Just look at Olympic swimmer Michael Phelps.

 

By Dr. Ben Lerner, the 1996 and 2000 Olympic Team doctor and New York Times best-selling author of Body by God: The Owner's Manual for Maximized Living. For more information visit him online at thebodybygod.com.