To reduce your risk of spraining an ankle:
Pay close attention to the surface on which you are walking, running or jumping
Do stretching exercises before and after any athletic activity
Do balance exercises
Wear well-fitting shoes that are appropriate for your sport
Avoid sharp, sudden turns and changes in direction
Strengthen foot and leg muscles by running, cycling or swimming
If you have had several ankle sprains, you'll need a good rehabilitation program that involves strengthening and balance exercises. You may need to wear a brace to protect your ankle as you recover.