Wouldn't this just cause muscle to dehypertrophy. Any size would come from cell swelling and water. Temporary gains.
No, not really.
That'd imply that muscles can't grow on high rep, lighter weight, which just isn't true.
The internet, and every one that uses it, seems to be stuck in this recommendation that Arnold made years ago that sticking between 8-12 reps at 75% of 1RM is the only way to build muscle. I agree, it's the most effective way and works well for beginners or anyone who has never lifted in that weight range but eventually we must begin to try other things to get growth.
There are two systems u can tax to get bodily adaptations, one works better than the other for growth but taxing both will net the greatest results in body composition.
The glycolytic system - which entails anaerobic work to exhaustion and the lipolytic system - which entails endurance aerobic training on the muscles. Notice strength training is not in this list. That is because strength training works the neurological pathways rather than the muscle itself. Think "spark plugs and wires" instead of "pistons and rods".
Anyways, strength training in lieu of higher volume training works great for muscle growth but strength training alone doesn't do it.
Giant sets and huge volumes of weight resistance training with short rest periods creates a huge pump, which if ur doing facial training in between sets, will eventually stretch the fascia beyond its previous boundaries, which then allows for more growth. FST-7, the current Mr. O's routine, is built around facial stretching using these techniques, along with Synthol or other oil based drugs to stretch the crap outta the fascia while training.
Btw, cell swelling is what u want. By definition, cell swelling is anabolic in nature and ultimately is EXACTLY what steroids and growth hormone do to the muscles.