What do you do for cardio when you have a sprained ankle?

Hi-

A great exercise is the laying down bicycle. You lay on your back and put your hands behind your head. Look straight up and don't move your neck. Then, pretend you are riding a bicycle. There is no impact and since your ankles are above your heart, you shouldn't have an issue with the sprained ankle.

Just one other thought, are you actively rehabilitating your ankle? You should also consider increasing mobility and strength in the ankle to make sure it heals properly. Also, by doing a good ankle rehab program, you will really speed up the healing process.

Best of luck.

Swimming. Get a water proof tensor. You can do "pull" - there are cheap pull boys out there, or pools usually supply them. They're pieces of foam you stick between your legs to keep them floating while you move your arms.

Try it out!