A mat includes a mat body defining an upper surface dimensioned for a user to stand on the upper surface. The upper surface is non-planar and includes at least one terrain feature defining the non-planarity. The terrain feature has a size that is on the order of magnitude of the size of the user's foot. Presenting this surface to the user may help remind him or her to move his or her feet to thereby adopt multiple poses, thereby preventing the user from maintaining any single pose for a fatigue-inducing duration.