A swiveling user support assembly has a user support or seat rotatably mounted on a user support mounting device or frame for rotation about a first pivot axis, while the mounting device or frame is pivotally or rigidly connected to a main frame of an exercise machine. The user support has a base, and a primary user support and stabilizing device mounted on the base. A pivot connection between the base and mounting device or frame allows the user support to swivel from side to side about the first pivot axis. A centering mechanism helps to orient the user support in a central position for user entry or exit.