Complicated question. You need to consider what compound you are taking and your genetics. Intense training doesn't just fatigue the muscle, but also the central nervous system. AAS CAN increase CNS output and recovery, but to what extent depends on the kind of training and what steroids you are taking. Rest is an essential part of training. Even if you can "train" non-stop, will you be able to really bring 100% for each workout without getting adequate rest? You will not. You see a lot of guy training 4 hours a day, 5-7 days a week, but look at their training. Light weights, bad form, tons of set+reps. They are just pumping the muscle, which DOES work very well on AAS.
Layne Norton is not natural, no way in hell. Regardless, he's strong and looks great. He has some controversial topics like making BCAA's out to be the holy grail of bodybuilding and saying permanent ********* down regulation is a real thing(which it isn't).