I had my knee replacements and spent ten miserable days in hospital. My recovery wasn't that good ... so I started a tunnel and then they let me out. The day after I got out I hired one of those indoor cycling machines. I couldn't even get my knees to turn over so I sat in a chair behind it to get things going again. Five days after release I was on the bike. Wasn't so funny when I drove into my grape vines. However, the next day I went around our block. The day after twice, then five times and then back on the road.
Cheers
Rob