28 yo hobby jogger here,
I started running only a year ago, I'm now running about 35mpw.
I've only raced one 10k so far, but I've done a few " time trials".
I seem to only be able to maintain my speed through the race and if I do a good job at it, I can squeeze a 100m kick at the end.
There's no way I can start to kick 400m before without dying at least 200m before the finishing line.