My gym, a Genesis BTW, for you other Kansans, Nebraskans, and Iowans, 2%, at best, I left disgusted. I hadn't been in a long while and starting to feel better I wanted to do something to not feel fat.
I started in the cardio room as the only person in a mask, which is understandable. I was on the bike and kept mine on, I wasn't exerting myself aerobically, but I was tolerant for those who were. While a bit nervous, I kept on going, until some [redacted] decided to ride, right next to me, not two machines done, right the eff next to me. I rode for two more minutes but then left disgusted. I went to the weight room with the intent of lifting, but I went in there and there was only one other dude in a mask, incidentally possibly the most fit dude in there. There was no one else in a mask in the entire joint; me, fit dude, the woman working the kids gym and one of the four people working the front desk.
I don't think there is a good reason not to wear masks while lifting weights, it's an anaerobic activity, especially when it's 5:30 at the gym, people are all on top of each other. I even intentionally went to the branch that would have more old balls people to avoid this. I guess I just have to go to the gym either at 2 in the afternoon or 9 at night.