
Oh I feel so much better now after doing cardio again!  After nuking my ankle by cycling 12hrs a day, day after day I had to stop all leg activity except minimal walking for four days. Today I got back on the (stationary) bike for an hour and it felt SO good. 
I was very careful not to use any calf/ankle/foot muscles, I pedaled with my heels, that is, I pointed my tibia at the pedals axle (see picture). My ankle is definitely gettung better but caution is called for so I dont re-injure
By the way, yes I do have big feet. These shoes are size 15.
