SalmonRice wrote:
You had a bad day. It happens. Move on.
I agree.
I see too much obsession with "PB" as opposed to "usual time" for -- it's as if one is supposed to run their "PB" every time. Of course, the more you work at something, the more improvement should be observed. Nonetheless, it's a "PB" for a reason.
I think your TT is right on where your 5k "PB" lines up. However, add the psychological aspect of all this: if you decide that 4:51 is disappointing, you will focus your attention on disappointment.
A "PB" is a "PB" for a reason. My "PB" for 5000m is 16:11, and I never ran an official mile in under 5:00. My usual 5000 times fell into the 16:30-16:50 range. I see no need for disappointment in running slower than 16:11.
Your choice: disappointment, or moving on towards improvement.