Certainly.
I definitely suggest reading through the stickies too.
A compound exercise requires the use of multiple joints and muscle groups.
An isolation movement revolves around one joint targeting a singular muscle.
Take the biceps for instance.
To train it in isolation, you would do something like a dumbbell bicep curl.
To train it in a compound fashion, you would do something like a dumbbell row.
bicep curl =
dumbbell row =
Note, I'm not suggesting these videos show proper exercise form. They do exemplify what I mean by the two exercises though.
With the former, you're really only targeting your biceps. (isolation)
With the latter, you're using your back/lats, shoulders, and biceps. (compound)
More muscles used = more efficiency. When dieting, you don't want to spend a huge amount of time in lifting. If you were to use primarily isolation movements, it would take you much longer to train your entire body since 1 exercise = 1 muscle, right?
So you want to utilize that efficiency associated with compound exercises. They, in general, also expend more energy. So they're better for muscle maintenance and they're better for caloric expenditure.
Follow me?
I should also note that there are times and places for isolation movements. Nothing is black/white, either/or in this field.
It was just an analogy.
ROI = return on investment.
What I meant by that, related to what I said above, is isolation exercises don't give you as much bang for your buck in the context of this discussion.
If I'm understanding you, it sounds like a front raise, targeting your shoulder. If that's the case, I wouldn't concern yourself so much with this movement.
This is basically doing the same thing as the first exercise.
It sounds like you need to restructure your program.
Most people are weak in these movements. It's not necessarily b/c you're weak either... the lever arm is really long in this movement. Fancy way of saying the physics and the angles of movement make this exercise feel harder than others that train the same exercise, thus requiring you to use less weight.
As someone noted above, eventually, and probably sooner than later, you're going to want to progress.
Dumbbells that don't allow you to adjust the weight really limit what you can do. Lifting weights is a stressor. Our bodies are highly adaptive and don't like stress beyond what they're used to. This being the case, when you place it under stress above and beyond what it is accustomed to, it's going to adapt to make this stress easier to handle.
In the case of weight lifting, this adaptation entails bigger, stronger muscles.
If you're aren't placing a stress beyond this threshold... adaptation isn't going to happen.
8 lbs in the beginning may very well be an sufficient 'overload' in certain exercises. You will undoubtedly outgrow this though.
Also, isolation exercises require the use of less weight than compound. So where 8 lbs might be heavy for your isolation shoulder exercises from above, the same dumbbells may feel very light for compound exercises for your shoulders, such as overhead presses.
I feel like we're really hijacking the thread. If people wish, we can certainly move this convo to my journal or something.
Questions?