Today's requirements of competitive bodybuilding make athletes to painstakingly сhoose the way they load their muscles.
One of the most crucial feature judges look at is the muscles symmetry which directly depends on the way athlete trains a separate muscle group. That is why the question of which type of movement is actually better is so true to life today.
As long as both isolation exercises and compound ones have its pros and cons, we gathered all the main characteristics of each side of the argument to finally make a verdict.
Bodybuilding isn't about moving weight. We go to the gym to build muscle. So we are interested not in pushing big dumbells but making our muscles work.
In order to achieve that you should isolate the loaded muscle group, so you can really focus on each contraction and achieve maximum motor unit activation.
On the other side, the more weight we take, the more motor units are involved in the work. In this way, we have to choose compound exercises in order to increase our feats of strength, therefore, involve more muscle groups to achieve desirable gains.
Here is what researches showed about this dilemma: studies using electromyography (EMG) to measure muscle activation have shown that compound exercises activate the major muscles involved in the movement as well as isolation exercises and sometimes better than isolation exercises.
According to Flex, studies on untrained subjects show that compound exercises produce equal increases in muscle size and strength as isolation exercises.
Brazilian researchers compared two workouts in trained subjects: compound and isolation exercises and compound exercises only. They reported no differences between those who added isolation exercise to their workouts and those who didn’t.
It goes out that both types of movement are just as effective at building muscle size as in increasing strength. Moreover, these studies didn't show a big difference in results in people training with only one type of exercises.
Muscle&Fitness advice athletes to vary their training routine with both methods because all of them are worth existing in your schedule. "Compound exercises stimulate more muscle groups and reduce the risk of losing muscle symmetry that can occur when focusing too much on a single muscle group. Isolation exercises should be used for specific muscles that need to be brought up or to reduce work for surrounding muscles that don’t need the extra work."