Once "restored" after 2 years of corrective diet, the too thin author just felt like exercising and he developed his own methods which all appear to be stretching and using gravity and only the body weight as the resistance.
I think in every case, a persons own body weight should be more than enough and a human does not need to use metal weight equipment to work out..if a human can support his own weight by his finger tips, he is a monster of a strong man in todays society.