Stop at a recreation shop where they sell exercise equipment, pool tables and the like. They can advise the square footage recommended for various pieces. The total space you require will be dependant upon the equipment. Our treadmill has rollers at the front so we can move it aside when not wanted. And, many ping pong tables fold for storage. I advise everyone beginning a project to develop a plan, to scale, on paper. You'll need to take into consideration wall placement, their thickness, anticipate any electrical, lighting and plumbing as well. I've included a copy of our basement plan from the link at "My Page". Good luck.

A few years ago I bought a large exercise ball with a cd teaching different ways to use it. You can sit on it and do stomach crunches, you can lay on the floor and lift the ball with your ankles, etc. I travel a lot for business and never leave home without my stretch bands. I bought them at sears- they are like giant rubber bands, really light weight, and can be used many different ways. And then there are always videos- yoga, pilates etc

Forgot to answer your other questions... I would go with rubber instead of carpet, you can always resell the rubber mat if needed and would be easier to take up when needed (no carpet tack strips). Shouldn't need to worry about getting water on the rubber mat to where as the carpet would soak through. I would probably have the floor finished no matter what as it helps protect the wood. Plus it will be one less thing you have to deal with when and if you ever take the floor up.

Artemis, being outdoors...yes! I have mostly been swimming. The pool heater from a local eBay seller has been wonderful. A while back I added some exercises with an exercise noodle. However, as much as I love it my body is getting too accustomed to it and I’m plateauing . I‘m also sort of tired of my many exercise video’s. Think I’ll start using my husbands new toy, the Snode magnetic fly wheel exercise bike. This is sitting in the living room for now but will eventually be in part of the guest room. My son turned us on to this inexpensive $330 bike. You can use zwift, peloton, fygnz & kinomap apps with but the easiest for us is to turn on YouTube and use the free GCN 30min, 45min and more vids. I have only so far used this newish bike while watching a tv show. You can not hear any sound from this bike while using. It also doesn’t take up much space. Me, looking through some of the free GCN YouTube vids. Most of these are designed around a geared bike workout but would be easy enough to adapt. EDITED to add... Further YouTube searches bring up some choices more up my ally, mixed workouts. There are many in non GNC as well.