The thread asking for 800 and 400 PRs got me to thinking about asking how to improve the 400 time as someone who is training for the 800. The aforementioned thread seems to suggest a pretty heavy correlation between fastest 400 time and success in earning a quality 800 time.
If that is the case, it seems pretty clear that having a fast 400 PR will return solid benefits in the 800. I know the "sub 1:50 800" thread has a lot of useful information, but I would like to isolate just the idea of improving the 400.
I am training mostly as just an 800 guy and will probably run some miles/1500s as well in the coming indoor/outdoor seasons. If you need more information, please let me know.
My fastest 400 right now is 51.07 open, 51.1 split and fastest 800 is 1:57.77 outdoor.