8x400 w/ a 75m jog + 55m walk. Equates to 90sec. Went 75-78-77-76-77-77-74-75, so first 1600m in 5:06, second in 5:03 if you add the 4's together. The last 100m I had to push myself more to hold pace, but it wasn't so hard that I couldn't of ran it in ~67. Current PR is 5:12 as of 10 days ago, went 2:37-2:35 for that one.