The bad news: not much. I started coughing 30-60 seconds into each of the walking segments. That's probably because I was taking deeper breaths, and those still make me cough. I expect that will go away soon.
The bad news for someone else: As I got out of my car when I got there, I noticed that another car in the parking lot had a window broken out. There was broken glass on the ground. When I looked up, I noticed someone with a gym bag heading for that car. I broke the bad news to him, and offered him sympathy. He said something got stolen-- "something valuable". I felt sorry for him, but only so much... it's stupid to leave "something valuable" visible in your car in a parking lot in downtown Oakland at midnight.