Ha, I remember similar, though that was only from about 3 years out of playing. We started with 1 x 800, 2 x 700, 3 x 600. At this point I was only marginally healthier than dead and fearing we'd then do 4 x 400, 5 x 300 etc but the running stopped after the 600s.
We then had to get through about 100 push-ups and 200 sit-ups before we could get the balls out. I'm pretty sure that did kill me given the extreme fatigue I was under at the time.
I've never found it so hard to kick a footy as I did after that reintroduction to football. Thankfully it got better, and reasonably quickly too.