A mat for standing comprising: an upper surface that accepts a standing user when the mat is placed on a floor surface; a length, measured across a greatest span of the upper surface, that is perpendicular to a greatest width measured across the upper surface, the length being no longer than 0.99, 0.92, or 0.86 meters (39, 36.3, or 34 inches) and no shorter than 0.66, 0.64, 0.55, 0.53, or 0.41 meters (25.9, 25, 21.6, 21, or 16 inches), the width being no longer than 0.64 meters (25 inches); a lower surface positioned substantially opposite to the upper surface and connected to the upper surface by at least an edge of the mat, an external portion of the lower surface contacting the floor surface; wherein the mat has or is adjustable to have a linear compression modulus, measured at the upper surface, over an entire range of available strain, the linear compression modulus having a given coefficient of determination value of at least 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, or 0.99; and the mat defining a line, parallel to the greatest span, that permits a user with shoulders, hips, and knees oriented parallel to the line to have a first foot position and a second foot position having the same relative intersection and angle to the line, wherein the first foot position is entirely within a center area of the mat and the second foot position is such that a ball of the foot is in a near edge area and a heel of the foot is within the center area, the mat having a lower compression modulus in the near edge area than in the remaining area, such that the position of the foot in the second position is in a less stable location than the first position, the mat thereby facilitating the user to more easily rock their foot due to the lower compression modulus in the near edge area which encourages more user movement. an upper surface that accepts a standing user when the mat is placed on a floor surface; a length, measured across a greatest span of the upper surface, that is perpendicular to a greatest width measured across the upper surface, the length being no longer than 0.99, 0.92, or 0.86 meters (39, 36.3, or 34 inches) and no shorter than 0.66, 0.64, 0.55, 0.53, or 0.41 meters (25.9, 25, 21.6, 21, or 16 inches), the width being no longer than 0.64 meters (25 inches); a lower surface positioned substantially opposite to the upper surface and connected to the upper surface by at least an edge of the mat, an external portion of the lower surface contacting the floor surface; wherein the mat has or is adjustable to have a linear compression modulus, measured at the upper surface, over an entire range of available strain, the linear compression modulus having a given coefficient of determination value of at least 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, or 0.99; and the mat defining a line, parallel to the greatest span, that permits a user with shoulders, hips, and knees oriented parallel to the line to have a first foot position and a second foot position having the same relative intersection and angle to the line, wherein the first foot position is entirely within a center area of the mat and the second foot position is such that a ball of the foot is in a near edge area and a heel of the foot is within the center area, the mat having a lower compression modulus in the near edge area than in the remaining area, such that the position of the foot in the second position is in a less stable location than the first position, the mat thereby facilitating the user to more easily rock their foot due to the lower compression modulus in the near edge area which encourages more user movement.