Gym

The gym: noise canceling earbuds or headphones work wonders. Some are quieter than other, and at different times. Most folks are at the gym to do thier own thing and are in parallel mode with each other so that's nice. Look on youtube to see how to use the equipment beforehand.We make our own accommodation.

The biggest hurdle for was the beign around other people but I soon discovered they are all in their own little worlds and don't really notice me. 

If you can't find one that's not too busy, it may also be worth looking at 24/7 gyms, and asking them what hours are usually quiet. Might mean working out at weird hours, but it would be a way of getting a quieter gym.

It seems that Arborfield Green Leisure Centre (in Berkshire) offers SEND sessions:

Reading Borough Council - Arborfield Green Leisure Centre SEND sessions

If that doesn't suit your needs, then I'd suggest contacting those gyms that would be the most convenient for you to reach and asking them the about the things that are most important to you.

For example:

• Do they routinely offer any formal SEND or quiet sessions (eg with no music playing, reduced / dimmed lighting)?
• If they currently don't, it that something they'd consider doing?
• What are typically the quietest times, with the fewest people using the gym?
• Etc.

By way of example, you could refer them to the link above and also to this article about the low sensory gym sessions that are offered by Active Gyms in Leeds:

Leeds.gov.uk - Active Leeds introduces low sensory gym sessions

No recommendation on the gym I'm afraid - most gyms need to be busy in order for their business model to work and for them to survice though.

I would suggest finding ways to cut out some of the sensory load here - good quality noise cancelling ear phones (ideally over-the-head ones or in-ear with loops over your ears to stop them falling out types) to reduce the TVs/music and grunts from overly enthusiastic weight lifters.

I doubt you can reduce the frantic nature of people though - most are in a high energy state needed to burn calories and meet their goals in the gym so this needs to be lived with.

You can work out which times it is quiet (ie ask reception staff) and go then if it is possible - not easy if you have a 9-5 type job.

Lastly how about doing the workout at home? Can you make space and get a gym matt and some adjustable weights? You can do a lot with this and get cardio from running or bike riding which removes the "other people" element from it.

Good luck on finding a solution.