That's a lot of unused equipment taking up valuable garage space!

I had my gym in my garage (3rd stall) for over 10 years. I actually planned for it when I built my home. I installed a "Cayenne" gas heater, as our winters tend to be cold and snowy. It served me well.

The only caveat is if you have equipment that may be sensitive to cold or heat. Treadmills and ellipticals could be compromised if you don't take precautions, like my heater. My garage didn't get below 50 degrees, as long as the door wasn't opened.

I got divorced and put up a new home with a detached garage. My gym is now in what my master bedroom was intended for. It works. You can catch a glimpse of my former gym in this video: https://youtu.be/1lTrMn8prgE

I include my reasoning for owning your own treadmill. Good luck!

We've had a commercial power rack, preacher curl, and upper back station in my garage for about 7 years now, along with a lot of olympic weight plates and bars. Nothing has rusted. The biggest issue for us has probably been dust. I open up the door and blow off the dust with a leaf blower frequently. In the summer, it's very hot in there, but with the door open and a couple of good fans going, it's not that bad. I absolutely hate cold weather, and even though we don't get cold winters in South Alabama, I still have a hard time getting motivated in the winter.