I'm looking to use these mats over a light colored berber carpet and am concerned that the suggestion of putting plastic sheeting under them to prevent staining will then make the mats slip and move during workouts. Any other suggestions?

The weight of our Impact Rolls over the plastic sheeting will be enough to keep the rolls from moving. The plastic sheeting will not act as a lubricant under the floor since both materials will cause a good deal of friction. We have had many people use plastic under our rubber flooring with no movement.