Abstract: A climbing mechanism is disclosed that comprises a central upright post with right and left foot pedal assemblies slidably disposed on right and left lateral sides of the post. Each pedal assembly is attached to a wedge-shaped slider that travels within a complementary shaped channel lengthwise of the post. Each pedal includes a foot-supporting sole portion and has a foot restraining strap. User-controlled pivoting of the pedals controls the mechanism that locks the pedals with respect to the post. Illustrative embodiments describe locking and unlocking arrangements wherein a projecting member affixed to each pedal assembly (such as a tooth or a cambered element) is controllably mated with a selected one of a plurality of sockets or recesses located lengthwise of the post. A further embodiment describes a locking and unlocking arrangement in which a braking member on each pedal assembly selectively positions each assembly through controllably gripping a cable disposed lengthwise of the post.