How come bodybuilding programs don't need to follow the rule if progressive overload? In that week after week its not about eeking small increase in weight you can, but mostly about volume accumulation and slight increase in weight lifted. Does overall volume really out beat progressive overload and growth response?
Posted the widely used and accepted study (god damn teekay) about that a few days ago. Muscles get larger in three ways, the cell walls thicken to handle pressure, I may be mistaken but I believe the mitochondria grow and then the cell expands to hold more fluid. You can also play with hyperplasia but that just means you got the cancer and you are gonna die so put me in your will.
+1 on both Easons and Tesseracts comments.
You have to stop thinking of just the weight on the bar. Progressive overload has more to do with increasing the overall tonnage over time, just not weight on the bar irregardless of volume. Tonnage is volume x weight.
Squats with a typical Bodybuilding style rep x set scheme: 200 lbs x 3 sets x 10 reps = tonnage of 6000 lbs
Squats with a typical Powerlifting style rep x set scheme: 315 x 6 sets x 3 reps = tonnage of 5670 lbs
The bodybuilding work in the above example is actually "heavier" work in the end, even it at first sight would not seem so.
Now, that does not mean that the BB work will get you a bigger 1RM, as pure strength also has to do with getting used to training with and feeling heavy loads. It could very well lead to more hypertrophy though.
I think higher rep sets and generally just higher volume make you store more water in you muscles, making you look bigger.