A ball bat includes a barrel in which one or more stiffening elements are located. The stiffening element may be positioned at a variety of locations, and may have a variety of configurations, for selectively limiting the barrel's performance without appreciably increasing the bat's moment of inertia. In one configuration, the stiffening element includes two radially outer flanges, a radially inner flange, and two web members connecting the outer flanges to the inner flange. The radially outer surfaces of the radially outer flanges contact, and may be affixed to, the inner surface of the barrel wall.