Barbells emerged as the Gold Standard progressive resistance training tool after the end of the Second World War. Sales of barbell sets skyrocketed in the 1960s when large retail stores such as Sears and Montgomery Wards began stocking inexpensive 110-pound "exercise" sets. The cost was kept to a fraction of the complex and expensive Olympic barbells: the exercise set consisted of a five-foot steel bar with a three foot "revolving" chrome sleeve. The 25-pound bar and weight plates were usually sold with two dumbbells. Millions of 110-pound barbell sets were sold worldwide. An Olympic barbell "set" was typically 315-pounds and would cost ten times the 110-pound barbell set. The 110-pound weight set introduced millions to resistance training.