Abstract: A treadmill folds for storage and includes a main frame structure, a pivoting frame, a resisting mechanism, an articulating structure, and an articulating mechanism. The pivoting frame pivotally mounts to the main frame structure along a main pivot axis such that a user may pivot the pivoting frame between a substantially vertical position and a substantially horizontal position. The pivoting frame supports a conveyor. The resisting mechanism applies a torsional resisting moment to the pivoting frame. The resisting moment opposes a moment which gravity induces on the pivoting frame. Upon moving the pivoting frame between the vertical position and the horizontal position, the articulating mechanism automatically articulates the articulating structure between a stored, retracted position and an extended position which stabilizes the treadmill.