1 workout will NOT in any way contribute to a large long-term gain. When someone does one of these marathon workouts what occurs is the body loads TONS of nutrients in response. The muscle worked goes up in size temporarily, but it is mosty nutrient loading.
If it were that simple to add muscle we would all be looking like Ronnie. Just do a 12 hour workout for each bodypart every other week and be the man you always wanted to be--LMFAO.
Quit reading "Flex" and you will be a lot better off. Most of the SHIT is made to sell magazines, not make you bigger.
IA