8 x 400 repeats

What an education! This was the most challenging thing I've done in ages, maybe ever. Physically it was within reach but the combination of my body complaining and my mind talking trash to me was interesting. This running game is getting more interesting all the time.

Are these supposed to be working my vO2max primarily?

I ran these today for the first time. Managed to bungle the chrono on #2  but I was able to get a little faster on each.

1:40
****
****
1:41
1:38
1:33
1:32.71
1:32.22

These were unlike any running I've ever done before. It was a real challenge to get through these.

Average HR = 146 / 83% Maximum HR = 169 / 96%

I seemed to recover well, but it became unmistakable that the load was increasing. I was short of breath in the last 50 meters of #6 and then by #8 I was puffing for all I was worth for the last 200 meters.

I just kept the tempo of my legs going and hoped my times would hold up.

I really haven't a clue what I'm doing. Is anyone willing to hazard a guess whether this is this about the level of intensity I'll benefit most from? Should I be spending more time in a deficit? Less time maybe?

Although it was obviously taking some serious demands from my legs, the lungs were heaving to capacity in the latter stages as I've described. Is this where the vO2max gets pushed?

This was an incredible run. It required a lot of focus I'm not used to while running. I'm as curious as all get all about what it is I was doing and what I was supposed to be doing. I know it took a lot out of me and that I'll need to rest well tonight.