Scratching comes from movement. Denting comes from DROPPING something. Since the machine will be PLACED on the floor (no one is going to drop it from an upstairs balcony). Staining is something you may have to deal with. You may not. Yes the feet may have rubber on them...but the small amount is fine. If it does stain a little bit, you can be content in the knowledge that you can always hide it with an area rug AFTER the work out machines are gone. Trust me when I say this, rugs and mats and rubber stuff can cause WAY more problems to a hardwood floor that 4 rubberized feet (per machine). If you really are worried then remove the hardwood (nope, not kidding) and store it. Then install some cheap cork flooring in there and go for the works you want. When you are done with your fitness studio, you remove the cork flooring and reinstall the hardwood. There. No harm no foul. But you don't NEED to do anything but put the machines down and live your life. Wood is AWESOME at being a floor. That's why the world has been doing it for 10,000 years (probably more...but historical records are hard to find on the subject).

Cork floating floor = fine. You can get very expensive and go with rubberized flooring...like $6-$12/sf depending on what you are after and your budget and how much noise reduction you need.

Unfortunately the office in the bedroom is for my husband as he is currently working from home indefinitely and needs the privacy for phone calls and Zoom/Skype meetings. I was planning to have my desk somewhere in the main part of the house as I work at home occasionally, I still go in the office. Our house is 3 Bedrooms, Kitchen, small Casual Family Room in front of kitchen, and large open room (formal dining/living room) in the front entrance that is open concept. unfortunately there are no nooks, basement, or attics in the house which is why our space is limited. Each of the 3 bedrooms has a purpose: Master Bedroom that has limited space, Husbands office and he needs the privacy for phone calls, and the current guest room which will be utilized as a nursery/kids room in near future. The garage has both our cars already and we live in the desert where it gets over 100 degrees. So a gym in the garage is not an option.

I like 3/8" rubber in rolls or mats. Some people claim they smell bad, but I don't find it objectionable and it dissipates over time. https://www.rubberflooringinc.com/rubber-flooring/index.html?campaign=105557825&content=646078963839&keyword=rubber%20gym%20flooring&gad=1&gclid=Cj0KCQjw7aqkBhDPARIsAKGa0oL3ZtF-9t8E06SHV-M8vokundu8N1vHYKIlLahKaaIMq1yGvAi-pXcaAkzoEALw_wcB