Mo: easy 60min@04:25min/km, avg heart rate=143
Tue: 20x400@ 74sec, rec 120bpm;
We: easy 50min@04:25, avg heart rate=140
Thu: medium long run 80min@04:25;
Fri: easy 60min@04:25;
Sat: LT intervals (always hard for me...)
Something is fishy here. If 50-60 min @ 4.25 is easy and just 20-30 more mins make the effort already medium, then you have problems breaking 1.30 HM and 4.25 is not your easy pace. Your 400s are OK, but you'll have to shave another 7-8s per lap to have a shot at 2.2x.