In one aspect of the disclosed embodiments, an inertial exercise device has an elongate member with opposing first and second end portions, and a sleeve movably coupled to the elongate member and disposed between the first and second end portions of the elongate member. A first elastic resistance element interfaces between the elongate member and the sleeve. A user-induced rhythmic movement of the sleeve along the elongate member alternatively toward the opposing first and second end portions causes the first elastic resistance element to alternately compress and extend as the first and second end portions of the elongate member oscillate relative to the sleeve.