In 1904 a Dane, Lieutenant J.P. Muller (1866-1938), wrote a book called My System. Its main theme was home gymnastics, and in five months, 30,000 copies were sold. This figure acquires additional significance, when one bears in mind the small size of Denmark with its then 2.5 million inhabitants. In one year, 20,000 copies were published in Swedish, 70,000 in German and more than 25,000 in English; 21,000 copies were to be published in the USA, 11,000 each in France, Czechoslovakia and the Netherlands and 6,000 in Finland. This explosive sale in a single year was followed by steady growth; by 1930 J.P. Muller's books had been translated into 26 languages and sold 1.5 million copies. One million copies were sold alone in English-speaking countries.

Muller was inspired by Greek gymnastics in antiquity. Even his image of male beauty was neoclassical in inspiration and consequently the first page of My System was illustrated by a drawing of a statue by the Greek sculptor Lysippos. This marble statue was called Apoxyomenos (the scraper) and the choice of this motif was no coincidence. Muller commented: “Much has been written about this statue, but all concur in praising its beauty, and in admiring the Greeks, who, by means of their athletic sports and gymnastic training, were able to produce human forms fit to serve as models for such sculptures. I have expressly chosen Apoxyomenos from among the many beautiful statues of antiquity to decorate the cover of my book because he is the embodiment of the contents of it: He is the athlete cleansing and caring for his skin after exercise, and thus the ideal towards which my book points.