Good point. I'd say its taken me ~2yrs/~100 sprints sessions to rebuild my training capacity to respectable levels.
For someone without a football/track background, I would say the learning curve goes something like this:
1 - become a pull runner (hams, glutes are the prime movers and not the quads. Think of "sitting back" while you run, hips should NOT be bouncing up/down AT ALL, keeping the transverse abdominus engaged etc. I know that "sitting back" comment is vague so def check out Minor and Boyce's sprint articles on this site)
2 - build up cardiovascular capacity thru repetition and proper preworkout nutrition (Finibar or good ole sweet potato work best for me)
3 - get lean (I'm really starting to think this is more important than #2. Or at least achieving this will allow for RAPID improvements in #2. In other words, now that I'm as lean as I was in highschool (read: no longer drinking beers semi-frequently), its no wonder I've regained most of that training capacity that I had way back when