Sub40 goal midlife crisis?

[Tallon]

Dear TheEd:

day 15 P=3'50

10min warmup + stretching
400m pace 4'07 bpm 129 effort 1/5
60sec rest
400m pace 3'46 bpm 143
60sec rest
400m pace 3'37 bpm 144
60sec rest
400m pace 3'44 bpm 148
60sec rest
400m pace 3'41 bpm 158
60sec rest
400m pace 3'37 bpm 159
60sec rest
400m pace 3'43 bpm 160 effort 4/5
60sec rest
400m pace 3'53 bpm 157 effort 5/5
60sec rest
400m pace 3'49 bpm 161 effort 5/5
60sec rest
400m pace 4'00 bpm 159 effort 5/5
60sec rest
10min cooldown + stretching

Feeling something in my previously injured right ankle and also right achilles tendon feels tired. I hope it is only adaption as tired ankle notions have gradually gone away during the timetorun training. This session requires extra intensity compared to the 2k and 1k sessions. My bad running form might start to be an important issue. I have read that you say that good running form comes naturally with speed ?

Kind regards,