10 miles with 5x1000.
Designed the intervals to simulate upcoming racing (such as Mayor's Cup) where the start is key, in that I want to be able to sprint out 100 meters at least before settling into 5:05 pace, otherwise, you get spit right to the back.
I warmed up for 2.5 miles and then started from a dead stop. I sprinted for 17 seconds, came down for a 1/2 mile, then sprinted again to simulate a surge before coming back to 5:05-ish again.
The first was a little slow, coming in at 5:03 overall pace.
The next 3 went 4:52, 4:46, 4:44 pace. I tried this method for a fifth, but the sprint at the beginning was too much after doing a total of 8 within the sub-5 pace already, so I stopped, reset and just ran a hard 1000 at 4:52 pace.
Felt like I really got good work in and didn't totally torch myself or break anything.