cam84william

I did it last year. There is a shop in the main soi of Jomtien complex, but halfway you have to go up the stairs. And then you see it.

Zing Resort and Spa in Jomtien Complex has a small Gym.

Here is a listing of the best gyms in Pattaya. There are others but maybe not as good.
https://pattayasanook.com/fitness-centers-and-gyms-pattaya/

Fitness 7 has a Pattaya branch...but I haven’t been there myself. 

Been a few years since I stayed there but just a wonderful Hotel on the River which gives you so much to do during daytime hours. Not only that next to the Skytrain, However late at night you may have to get taxis to get home. Don't think anyone will bother you with presentable guests but I always advise to book the room for 2 people . Makes it more unlikely that they will bother you.
Recent reviews say the rooms are getting a little dated . Aren't we all? The staff, location, restaurants, pretty sure you'll love it.

I'll be staying at Shangri-la later this year.  Has anyone had any experience there?  Are they ok with "guests"?

Just did this flight last week (expect to be late...all of my VN flights were late). Yes, VN gives you access to the fast track immigration line. I believe they gave me the fast track pass when I checked in at SGN.

Some airlines have withdrawn their priority service for business class passengers. This is because airlines have to pay for each passenger using those priority entrances. Check directly with a Vietnam Airlines office otherwise you will probably get the runaround with different people saying different things.
Seems there is definitely a Fast Track Service within the East Immigration Hall specifically for THAI passengers. This photo was posted on the ThaiViss forum some months ago -

As for the names given to the Fast Track lanes, I understood = and asI have seen for some time now - that the other dedicated channel between the east and west Immigration areas uses Priority Lane for both outgoing and incoming flights. But irrespective of name, it will either be Priority, Premium or Fast Track. As with the above question, why don't you just call THAI Airlines and ask them to find out for you. No guarantee, of course, that someone with actual knowledge will answer you. But the ground staff at the entrance to the aircraft as you disembark will.