Thanks for all the suggestions to this week's strange encounter, in which wrestling Marines kept colliding with me as I worked out on a rowing machine at the gym.
I ended up doing c) Continued rowing as if nothing was going on.
After the second hit, I saw I had 7 minutes left and dug in to make a point. I rowed even faster, as if that somehow was going to speed up time. But rowing machines are noisy and the extra volume, let alone my determined, stone-face expression, caused a couple of guys to move closer, if only as a symbolic gesture of protection. I probably reminded them of their mother.
I left soon as my time was up, and I likely was a topic of a conversation. Or maybe not. These guys have dealt with much worse.