I hear you... it kills me that I'm "not the man I used to be".
But I can walk, so that's a plus.
The priests must be conditioned to it. I only recently started doing a full aarti with the panchaarti diya in my puja. Even though it's little (this is the exact one), holding and circling it for the 5 mins. of the song was making my shoulder sore. I seem to be getting used to it. It's a movement I never did, even in the gym. I also sometimes hold it with 2 hands. So, I think they're used to it. I see pictures of the gigantic ones at the Ganga Aarti at Varanasi. Those things are
hyoooge and must weigh 1/2 ton.