Abstract: Gymnasium equipment has a vertically movable column on the upper end of which are a pair of arm retention tubes which will accept arms of various items of ancillary equipment to perform a range of gymnasium functions. A gymnast will cause the ancillary equipment, and therefore the retention tubes, to rock about in horizontal axis, and in doing so cause a piston to move in or out of an hydraulic cylinder, displacing oil from the cylinder through a valve at a rate which is adjustable. With simple and inexpensive ancillary equipment, the invention makes it possible to achieve many different gymnastic functions.