Thursday fine tuning

Last session before the Brighton race. Thought I'd test myself over 400.
Session was 2x(250+150) with 30 seconds and 10 mins recovery.
The idea is that the total time is roughly your 400 pace.

Ran both 250s in 34 seconds, which I was pleased with, but both 150s were in 22 into the wind; disappointingly slow.
So totaling 56. I was hoping for sub 54 at this point.
Need to up the ante on Saturday.