Unusual run. I didn't want to do the trails for another day so I ran on roads, found some decent stretches without too much ice but nothing great. After 4 miles I headed indoors to the treadmill to semi-join some coworkers. I chose interval workout to break up the monotony, but it only changed incline, not speed (BTW, this treadmill was crazy, it can go from -3% to 30% incline! that is crazy, I hit 15% for a short while and that was probably the most inclined I've ever been on a treadmill as well as difficult to run even >7min pace). After some new experiences with inclines, I started picking up the pace alternating 1min fast, 1min slightly slower but still fast, eventually running <5:30pace. I didn't really have a plan for this workout, I just knew I wasn't going to sit on a treadmill for 30min without changing the speed.