Notes
I ran 15 minutes of warm-up, then 1 min hard, followed by 1 min easy. Then 2 minutes hard, and two minutes easy, and finally 3 minutes hard and 3 minutes easy. I did these for a total of 4 sets, with a final 1 minute segment to finish it up, followed by 15 minutes of cool down. (actually 18:32 cool -down.)