The first several weeks I do my speedwork on the TM because it's easier to let the machine push the pace. Today was half mile repeats - I started at 5k pace (8:15) then went 0.1 mph higher every 10th of a mile, then I took a quarter mile break to drink water and wipe away the sweat. Pretty typical speed workout.
As I was leaving, a very heavy man thanked me. He had been walking a few treadmills away from me. He said normally he would have quit, but seeing me do my repeats inspired him, and he went 1.5 miles today, his farthest ever. Awesome! So often runners get so stressed about minutes, heck seconds!!! on our times, and today was a good reminder that there's a bigger purpose than shaving off a few seconds.