Yesterdays workout on the treadmill was this. 30 minutes over before you know it.
You have two 10 minute runs separated with a 5 minute HIIT and one more round of the HIIT when you finish the 2nd run.
The 10 minute runs are the same..... the only difference is your slower paces are in the reverse order on your 2nd 10 minute run.
Remember these are the speeds I did. I also had my incline at 1% . Adjust the speed to make it work for you.