I have two grown kids. They were never second to anything. That didn't mean not running regularly on my part.
I once spent at least five hours, probably more, in a hospital waiting room with my mum while my dad had big time cancer surgery. No one came out and said how it was going. I was useless there. I wandered around the halls just to see something other than the waiting room. I read a book I'd brought, glanced through the newspapers and magazines on the tables, watched the TV, went to the cafeteria not so much because I was hungry but for something to do and to be somewhere else. My mum and I traded off "wandering" time so someone would be there in the unlikely event someone actually came out and told us something. I was anxious as can be about how it was going and simultaneously bored as could be. I did not run while this went on but if I had it to do over again I think I would have. It would have helped the boredom and anxiety and would have had absolutely no effect on how well or poorly the operation was going.
But none of that matters because YOU wouldn't do it so it's a bad thing even though you can give no specific reason, i.e., an actual negative effect on the likely success of the surgery, as to why that's so. You're entitled to your opinion but that's ALL you have here. No one on this thread has given an actual bad thing that happened to this kid in surgery because her dad ran a mile while it happened.