Keeping fit following injury

Dear Daniel and Kelly, I’ve been a big fan of your site since the beginning. It’s terrific. A couple of days ago I ruptured my Achilles’ tendon playing ping pong (can you believe!) Its probably going to take a year for me to regain full mobility during which time I’m going to lose cardio fitness. My challenge is to maintain strength and flexibility during rehab. Any chance of producing a video of work outs that can be performed in a cast/protective boot? One of the biggest challenges for me is how to warm up (when I’m immobile) so as to prevent injury. Best Carl Smith