To be fair to Arnie, it was not his workout program that made him smaller than the big boys of today. It was a combination of the era, the gear, the recovery and nutrition. These days the true big guns of the competition world are using much more hgh (arnie’s day they only got limited quantity of cadaver hgh) they are using insulin as well which was not commonly used in arnies era, along with tren. The era of arnie and franco, they were much more focused on proportions and symmetry, than mass, infact most of todays bodybuilders would probably not do so well in arnie’s day. Also he is known to say “you only need 6 hours of sleep”. Last but not least nutrition was not as good as todays, we now know more about the bodies anabolic cycles.
Some bodybuilders and athletes use trenbolone esters for their muscle-building and otherwise performance-enhancing effects.  Such use is illegal in the United States and many other countries. The DEA classifies trenbolone and its esters as Schedule III controlled substances under the Controlled Substances Act .  Trenbolone is classified as a Schedule 4 drug in Canada  and a class C drug with no penalty for personal use or possession in the United Kingdom .  Use or possession of steroids without a prescription is a crime in Australia .