This was the main question I had when trying out the Nobull trainers. The very first day I wore them, I was able to put them to the test when I saw that part of the workout was a timed mile. They were awesome! They felt great to run in, and I didn't have any knee or foot pain afterward, which can sometimes happen when I'm not wearing supportive shoes.
Throughout the next few workouts, they also felt great when doing shorter sprints. I do think that if workouts have longer runs programmed, I'll do what my physical therapist recommends and wear running-specific sneakers, since I have a history of knee pain and plantar fasciitis.