Are Isolation Movements Better for Muscle Growth?
To isolate or not to isolate, it’s a philosophical question.
Without a little more context, some people tend to get a little attached to the story that speaks to them.
Some people shun single joint isolated movements for the more “functional” compound movements.
Others almost entirely isolate to “avoid injuries” or they use a single body part split to maximize “time under tension”.
Like many contentious issues in the gym, camps were formed, tents were pitched, and trenches were dug.
Compound movements like squat, bench, deadlift, rows and all other multi-joint movements are effective and efficient.
It is clear that most compound movements found in most strength programs build mass, improve body composition, and most directly improve absolute strength.
The thing about it is that they create more central fatigue - meaning that the brain triggers task failure at the end of the set before the target muscle fibers are exhausted. Which, in turn, lowers the ceiling of mechanical stress to target muscles that we can apply during a certain session.
Single-joint movements, on the other hand, create less central fatigue during a set. This means that with all else being equal, you can get more muscle activation, more tension on all fibers, and more fatigue each set for a given target muscle.
Ultimately, it shouldn't be one or the other. Hypertrophy is limited when strength movements aren’t incorporated because you can’t change the size of a muscle that you can’t reach.
After digging into some of the details, we should all be able to acknowledge and recognize that a balanced training program should include a mix of both isolation and compound movements.
It’s a matter of experimentation, balancing adaptation, and fatigue.
The takeaway for most people, here, is that it’s a good idea to keep compound movements the focus of your efforts and use isolation movements in your accessory or assistance work to get additional focused hypertrophy work in.
Hope that all makes sense!