I had planned to make the track for this session but time was against me. So instead I used the treadmill like I did last time I did this session 2 weeks ago.
Same routine, a 2km warm-up, then some very quick strides to spike the heart rate and then into it. Recovery was only 45 seconds compared to 60 seconds previous so I thought 21.8kms/hour (66 seconds per lap) would get that heart rate up for each 400m. After the first 3 I was only in my threshold zone and from there on in I was playing catch-up. I kept upping the treadmill by 0.1kms/hour each rep and by the time I reached no 10 I still wasn't in my tempo zone...
Speed was very quick by this stage and managed to get into the zone on reps 11 and 12. Feeling guilty I decided to do a couple more (still increasing the speed each time) and again I was up into my tempo zone. I should add that I was still running 66 seconds each time even though I was down to 63 seconds for the 400m by the end of the session.
So a big improvement on 2 weeks ago but I wasn't putting the heart rate where it needs to be so a fail as far as the session goes. A 2km warm-down and that's 9.6kms for the day.