I would soften up some of the surfaces, you can use a few rugs with good back gripping, maybe set your equipment on rugs, or place one beside each piece, you could add a few soft chairs with pillows and brighten up the space with like an ocean blue wall and paint the rest sand color. It would be so pretty and relaxing. A few peaceful ocean pics on the walls and you'll have a paradise to work out in.

You might could use fabric wall hanging to soften the space.

You could even make a scrap wood wall like this to add a natural element. https://www.hometalk.com/3254469/how-to-install-a-scrap-wood-wall

How To Install a Scrap Wood Wall #WallCandy

Or if you can find old windows, they could be fun https://www.hometalk.com/28820149/custom-stained-glass

Turn An Old Window Into Wall Art

You can use fish net on the wall to start with.

The magic of paint! Here's how I updated one: https://bachelorettepadflip.com/2017/08/04/flip-4-friday-feature-the-basement/