It depends on how bad your injury is. When I went through a pretty serious sprained ankle injury, I did a lot of physiotherapy exercises for improving the stability and the ROM of this area before starting leg training again, including treatment with electricity and a very painful stretching massage. Only about 3-4 months after the injury I started working out again, starting with a high rep range (about 15/set) and putting a little effort into separated legs exercises (lunges, single-leg leg press, etc).
My conclusions are the following:
- Getting back your stability and ROM is extremely important. My physiotherapist said I could stop when the leg was "almost" back to normal, but today, almost a year later, I still feel a difference in the ankles functioning. Keep going with this training even if you feel your functioning is relatively fine, because the process "stops" when you stop practicing.
- Do single leg exercises. Lunges, single-leg leg press and later single-leg squat, single-leg leg curl, and maybe even single-leg calf raise (though I didn't try it myself). The strength difference between your legs increases on every day of "rest", so this is important for "balancing" your muscles.
- Get back to everyday functioning as soon as possible (recommended by your doctor, of course), in order to shorten your recovery period.
Hope you'll feel better soon!