5 Minute splits are a pretty standard interval and can easily be fit into an hour long workout. they should get progressively harder and your 8 out of 10 effort should yield diminishing speed the farther into the workout you get.

1. Warm up for 10 minutes
2. Jump to 8 out of 10 effort for 5 minutes
3. Step down to 4 (recovery pace) for 5 minutes
4. Repeat