Wow -- thanks for this, George. I had set as a goal for myself for 2008 to run a sub-60 400m, before I found CrossFit. Sadly, strangely, I've only run the 400 three times (got a :70, :63, and :62). That last :62 was very strange -- I really expected faster, but I've also gained some 15 pounds, from 196 - 211 pounds --- I had extra energy and wind at the end but my legs were feeling thick and, er, like mud or brick, and simply wouldn't turn over faster. It was really frustrating.
I need to get video. I think my turnover is way too slow. I was a distance runner for about 20 years, and I think I habituated slow hips because of it.
I can't wait to get some sprint and POSE training. I'd really love to see CrossFit focus on something like 40 Speed: http://www.40speed.com
* * BTW, I just posted on my blog today about running with a bunch of good links / references at the bottom of the post: Running: Speed Is Wisdom
You might find the links useful -- it's pertinent stuff.