A fastener for a fitness equipment superstructure includes a stud member and a peg member, both of which include a head and a body. The body is sized to be received in holes on uprights of the superstructure to attach one or more accessories thereto. The head is significantly larger in diameter than the body, but thin with a circular profile and radiused corner. The stud member includes a thread portion which mates into a threaded recess in the body of the peg member, with the heads opposing each other on opposite sides of the upright.