During his bodybuilding career Arnold Schwarzenegger performed mostly supersets to gain maximum growth for his chest and his back. This allowed him to handle more weight and helped him develop greater muscle density.
His training regimen was not for the weak or the novice, since even experienced bodybuilders could not handle it. Slowly making progress is recommended, because his routine takes a toll on your endurance and stamina.
To get the maximum growth Arnold would put on the heaviest weight he could handle, when training his chest. He normally would perform pyramid sets, increasing the weight and decreasing the repetitions simultaneously per set.
As if that was not enough, Arnold would hold certain poses between the sets and after the workout to increase the intensity. This in combination with squeezing the muscles at the top of each rep would pump up the muscles like a beast.
One of the chest routines of Arnold Schwarzenegger: