Anyways, here's what I did. I repeated each circuit 3 times before moving on to the next one.
15 minute incline walk (speed 4.0, incline 15.0) - I'm going to decrease to 10 minutes next time to keep this under an hour.
Circuit 1
1 minute plank
15 butt/leg lifts (slow with control)
Bear crawl (for about 30 seconds)
Circuit 2
45 second plank/side
15 bicycle crunches/side (have both legs fully extended and a few inches off the ground before bringing the next leg in)
Crab walk (for about 30 seconds)
Circuit 3
15 cable rope cruches
15 SB roll-outs
V-sit twist (50 total)
Circuit 4
15 roman chair leg raises (legs straight)
15 back extensions
Mountain climbers with a twist (knee to opposite elbow, fast, 50 total)
Sprints 5 x 30 seconds, 15 second rest. I was at speed 10.
Cool-down walk to lower HR. Mine was about 2.5 minutes.
Not too bad for an ab day!
Feel free to comment below or email if you have any questions about the exercises :)