Costco (in Canada at least) has these sweet rubber mats that remind me of the gym. Way cheaper than Amazon since they are heavy as heck! It's flat on the other side :
The Best Gym Flooring of 2023 - Top Picks by Bob Vila
Rubber Flooring Rolls - Rubber Flooring Direct
Gym And Physical Therapy Center Floor Cork Works So Well - ICork Floor
What's the Best Flooring for a Home Gym? | Flooring Canada
Rubber Gym Flooring Canada | Gym Floor Mats and Tiles
Rubber Gym Flooring Canada | Gym Floor Mats and Tiles
What's the Best Flooring for a Home Gym? | Flooring Canada