“Samson didn’t eat steroids, and Hercules didn’t need expensive running shoes - they had a mind! You don’t need a cool gym or expensive sports equipment to become as strong as me!” In his book “Solitary fitness” (exact translation: good physical shape in an isolation cell) he doesn’t come up with anything new, he brings together everything that humanity has learned in the process of physical self-improvement. He divides training into two parts that depend on each other: training the body (various techniques) and caring for the body (nutrition, cleansing the body, and so on). Charles is an adherent of isometrics, static exercises, oddly enough, but he bypassed side and did not indicate the name of Alexander Zass, who pushed isometrics to the masses.