Indoor Friendly Sled???

I will most likely be lifting at a new gym in the office building I work at. Around the time my shifts end, the place is dead empty. It has a massively long aerobics room. I want to be able to do towing work for sprints and such in there.

Anyone have an idea of how I can do this indoors and not wreck the floor? I was thinking of getting a padded duffle bag (like a small sleeping bag), and putting some weight plates in there. Then I can slip a rope through the plates and have an O-ring on the end to keep them from falling off.... has anyone tried a different method?

C

Thats a good idea. Or you could probably rig something up w/ a heavy-duty piece of carpet.