Fast Travel journeys that take an hour or more of game time will restore you to full health.
Using Fast Travel while on foot can cause your horse to wander off from it's last known position, if you use it too many times without being mounted. Your horse will attempt to make it's way (very slowly) back to the stable where you'd acquired it. To avoid this from happening, never fast travel more than 2 or 3 times without locating your horse and mounting up first. When you fast travel to the gate of a city or town, the horse will be moved to the stables nearby. After conducting you business in the city, you can then fast travel to the city stables and your horse will be waiting there for you. If you wish to travel on foot for a while and don't want your horse to wander off, leave it at the stable where you'd acquired it then set out on foot.
==Alternatives to Fast Travel==