not all compound movements are necessarily better than isolation movements.
the essence of the the difference lies more in the mechanics of most compound lifts in contrast to artificial or machine movements.
With compound lifts, you may be able to cheat the poundages a little bit through swaying, swinging, kipping, or leaning, but you are still employing functional strength against real world resistence.
Many artificial movements do not have a real world equivalence in functional mechanics. You may be able to see some specific adaptation to that stress, but it usually doesn't translate into genuine functional or power stress.
one man curls 100lbs
another man deadlifts 600lbs
assuming thats all they did who do you think is bigger? and why?
ill let you make the connection
I'd say Torrok's post sums this thread up
What about a man that curls 250lbs. and a guy that deadlifts 250lbs.?
Well the guy that curls 250 has to lift it off the ground first...
and if the guy can curl 250, he can certainly dead 600 pounds, probably a lot more. that is insane Ronnie Coleman type weight.
compounds allow one to move more weight, so this one is pretty much a no brainer.
Compound movements incorporate more muscle groups to perform the exercise. More overall growth, thicker/denser muscle mass, and the ability to utilize the strength in real world applications.
Also, just because they are compound movements does not mean they are free weight movements. Something to think about as to which is better...
Your stranded on an island, about to die from hunger. You see two trees. One with massive giant oranges, the other with tiny ones. You want to get the most food for the effort you put in peeling. Do you grab the small fruit or the big fruit?
Compound movements allow you to use your energy effectively and use as many muscles as possible.
What everyone else has said, plus compounds release more testosterone.
The most appealing argument to anyone training for anything beyond mere aesthetics should always be that they want to be good at something useful. ;)
Apparently compund movements yield a better response from the endocrine system as well, i.e. a hormonal response that promotes better muscle gain overall. Hormones play a huge part in the whole muscle building/fat burning process, let's not forget that.
It does remain to be said that very few people in the gym neglect upper body compound movemts (most do neglect deads and squats). I haven't seen anyone who uses solely isolation movements (usually only women do this) make any noticable gains.
Compound movements involves more muscles than isolations. That alone is enough reason to do them...
isolation exercises are better :outnumber: