Sweaty arses in my coffee shop

Hi all, maybe not a big thing given the state of the world at the mo, but on couple of mornings a week since I retired I like to linger over a nice cup of coffee in my local Costa. Its got handy parking and the staff are very pleasant so it has been a nice place to relax in. But, in the last couple of months a group of middle aged guys have started coming in after meeting up for a run. Whats wrong with that you might say, its sociable and they are getting some exercise? Well before they come in they stop at their cars and get towels, start wiping off the sweat thats pumping off them and come into the shop, still pumping and wiping while they are in the queue. Then they sit down on the fabric seats and have their coffees, maybe 5 or 6 of them, ive seen sweat dropping off tthem as they pass my seat and there is a pretty good unpleasant whiff too. I think its gross but I know that saying anything to them would result in abuse if they are happy to sit there in that state, even though there is a decent outside area they could use instead. So should I leave it alone and change coffee shops, say something to the staff, email head office about it? Or maybe I should join them, being a fat aul lad who spends too much time drinking lattes!