High intensity training can be used to maintain muscle size however it is too dangerous to use to grow. Injuries must be avoided at all costs in bodybuilding.
The typical formula for huge size is volume with a reasonable resistance. That was true 40 years ago and is true today.
I never had the stomach for high volume. I hated those 25-set marathon workouts to where I stopped looking forward to the gym. Lee Haney was actually the first guy I remember speaking about doing fewer sets, so I figured why not. Worked great, I never looked back.
Dorian just took it to another level with the intensity.