The "posh" Gym

I've been away for a few days, just needed a short break as we were unable to go on holidays this year.
So we went to Northern Ireland for a bit of retail therapy (many things are cheaper in NI than in the Republic of Ireland) and a break.
For the last day and a bit, we've been staying in a hotel in Belfast. Part of the great deal we got via the internet was that guests can visit one of the "Members Only" gyms in the vicinity. I won't mention the establishment, but it's a well-known UK leisure club.
So I went to this leisure centre this morning, produced my hotel room card and was shown around by a member of staff. Wow! Star treatment for a non-paying visitor!
Afterwards, I went to the gym. I'd never seen a gym this size. For some of you out there, this gym would be the norm, but for me it was awesome! About 10 times or so the size of my local gym and maybe 120 machines plus free weights and a corner for boxing. That was just the gym. In addition, they had tennis courts, indoors and outdoors, and 2 swimming pools, one indoors and one outdoors.
I didn't know which way to turn when I entered the gym. So much choice! So I worked my way around. Warmed up on the treadmill, then went to the free weights section and afterwards to the various machines for weight training.
Boy, they had some machines I'd never seen before and I had no idea how to use them.
Fortunately, they had several instructors on duty who were more than willing to help.
So I used a few of these new machines.
After maybe an hour or so in the gym, I went for a swim outside. Weather wasn't great, cool and showery. After no summer for the third year running, we've gone straight into autumn/fall, but the sun was out for a little while today and the pool was heated. So that was great!
But then it happened: as soon as I had showered, my shoulders started hurting. Well, maybe my right shoulder was hurting a bit before I went to the gym (slap on the wrist, shouldn't have gone!), but now it was hurting a lot.
But as it was only 12pm, we went into Belfast city centre shortly afterwards.
The pain didn't improve. No, I don't think that there's anything wrong with me as such, but the machines I wasn't used to could've aggravated the pain in my shoulders. I've realised that as you get older, it takes a lot longer to recuperate from strenuous physical exercise and for whatever reason, my shoulders decided to pay me back for the punishment I inflicted on them in the gym this morning.
Yes, I really don't enjoy that side of being middle-aged, but I don't think I have a choice in this matter.
With a bit of luck, I'll be better in the morning.