Abstract: An aerobic climbing step/bench device includes a base in the form of a horizontal platform having a downwardly extending apron. Height adjustability is achieved by the use of detachable legs which are mounted to the base by mounting elements and complementary mounting elements on the legs and underside of the base. At least one set of mounting and complementary mounting elements includes a cylindrical post and a recess shaped to receive the post.

Abstract: A ladder with anti-deformed side rails comprises two tubular side rails, a plurality of rungs, and two tubular inner bushings. Each of the bushings is tightly fitted with the inner surface of each side rail respectively and passed through by the respective end of the lowest rung. Additionally, the longitudinal length of the bushings ranging from 2/5 to 3/5 of the distance between two neighbor rungs, and the thickness of the bushings ranging from 4/5 to 1 of the thickness of the side rails lead to an optimum bending strength for the side rails.