400s

For 20 minutes:

Run 400 meters
Rest precisely the time of the previous run

Completed 7 + 1

1:08
1:19
1:19
1:22
1:26
1:31
1:30
2:30(started walking the 400 as soon as I finished the 7th one, after 90 seconds I finished the 400 running.  or else I would have just rested at the end of the 20 minutes.

I did not warm up enough and the first one was too fast in the Oklahoma heat which was humid and 103.