If you don't require oil/similar resistant flooring you can get foam tiles off ebay cheap. We got a load when child no1 was learning to walk. They can slip a bit, so I'd be tempted to spray a light coating of adhesive to make sure they stick.
Our shed and brick outhouse have vinyl installed by the previous owner. Although it's not the slickest look it's quite effective. And I assume was cheap. So in the first instance that's what I'd do instead of paint.
That would be my inclination. Surely you're going to have the weights in one area? I think a surface that is suitable for a workshop and will withstand weights being dropped will be quite expensive.
If you don't require oil/similar resistant flooring you can get foam tiles off ebay cheap. We got a load when child no1 was learning to walk. They can slip a bit, so I'd be tempted to spray a light coating of adhesive to make sure they stick.
Our shed and brick outhouse have vinyl installed by the previous owner. Although it's not the slickest look it's quite effective. And I assume was cheap. So in the first instance that's what I'd do instead of paint.