1. Cross country skiing - again, not high impact, but great whole-body exercise, safer than downhill skiing, and gets you out in the fresh air.
2. Platform tennis - a racquet sport that is great for bone strength and is played outdoors all winter.
3. Pickleball - another racquet sport that is played indoors during the winter months or outdoors in warm seasons.
4. Wallyball - a fun, social, relatively new sport that involves jumping and lots of movement which can help build bones.