Back on the marathon plan

need to find a goal for my training, been slacking as of late.
Xmas, food and booze taking over.
I decided to redo the marathon plan to try and get some basis for a faster, fitter me.
I really would like to go BRIC or even and the crash-b this/next year in celebration of the half a hundred candles going to burn on the next birthday cake.

Training today was adapted from the Eddie Fletcher Marathon Plan:

3 x 30 minutes with 3 minutes rest between intervals

Heartrate cap = 148 limit for UT1

Rate cap = 20

Idea is to power doing R20 until the cap is hit then lower the power to keep within a few beats of the target.