I sprained my ankle last fall and it took several months before I was walking and riding without an ankle brace. I first rode 5 weeks after the sprain, but then only sparingly for the next month -- I couldn't easily twist my foot to unclip (it was my "dominant" unclipping foot) and sudden, unexpected movements were painful. My exercise during most of this period included the resistance ball, stretching, light weights. I did lose some aerobic fitness and conditioning, but only temporarily.

I was told the reason it took me so long to heal was that I didn't stay off my feet entirely at the beginning, but who can stay on their rear for a week?