Muscles make a man

Middlesex, NJ : Margrave Corporation, circa 1970. Mail order catalogue, quarto, pp. [12] with order card, illustrated in colour.

Illustrated catalogued for the ‘Bullworker’ isometric exercise device. ‘Burst out of your shell and be a REAL man’. ‘5 minutes a day must get you in MANSHAPE’. 

‘Bullworker is a product and fitness company that specializes in isometric exercise, that is the static contraction of a muscle without any visible movement. The original portable home fitness device was invented by Gert F. Kölbel in 1962. The product enjoyed widespread popularity in the 1960s and 1970s during the personal fitness craze, but its popularity fell off in the 1980s when personal gyms became readily available. New models have been made available, and Bullworker is still marketed worldwide by different holders.’ – Wikipedia