Most of you know this, but I need to say it to lay the foundation for my argument:
There are two primary types of movements: isolation and compound.
Isolation exercises emphasize movement at one joint; compound exercises incorporate movement across many joints.
Let's say you want to build up the strength and size of your quadriceps. Depending on what training school you belong to, you could do leg extensions that isolate the movement at your knee joint; you could perform leg presses that also involve movement at the ankle and hip; or you could perform front squats that add in the low back, along with abdominal and upper back components.
If I didn't give you any additional info, which choice makes the most sense?
Sure, the front squats.
Because God Said So
No matter how hard you try, you can't perform an isolated movement in the real world. The reason is because your body is designed to work as a system of integrated parts. Reach out for a cup of coffee at the kitchen table and you're recruiting muscles at the shoulder, elbow, and wrist joints.
When training with free weights, it's difficult too, even if you're trying to isolate. Perform a standing front raise with dumbbells for your anterior deltoids. The first muscles that fire are your calves, followed by your posterior chain and abdominals. After that, your deltoids fire to lift the load.
With the help of machines you can be pretty damn effective at isolating muscle groups. Take the one-arm dumbbell preacher curl, for example. This is about as isolated as it gets for the biceps. The movement is isolated to your elbow joint. And since you can rest your upper arms, your traps aren't activated. Neither are your upper back muscles activated.
About as isolated as it gets.
Show me one elbow flexion movement in the real world, though, that doesn't involve your traps. For that matter, show me one that doesn't involve the upper back to any degree, either. You might come up with one or two that don't involve the upper back, but there aren't many.
My point is that the traps and upper back are designed to work with your biceps. Taken a step further, I think it's useless to train the biceps unless you're also working your traps and upper back.
Parting of Ways
And this, my friends, is where the parties split. The isolation camp usually favors isolating the biceps, traps, and upper back. The compound camp favors pulling exercises for the biceps, along with exercises that also involve the traps (such as standing barbell curls). So we're not dealing with an argument over whether or not a standing barbell curl is useless. Of course it's not. Both camps would agree.
What we are dealing with is the question of whether an exercise such as a one-arm dumbbell preacher curl is an intelligent exercise choice.
In my business, the answer is simple: since the biceps are designed to work with the traps and upper back, I won't use any exercise that doesn't also activate at least one of those two muscle groups. Sure, you could isolate the biceps, traps, and upper back with three different movements, but why? The body isn't designed to work that way and it's inefficient from a time-management perspective.
I'm only using the biceps example because it's easy to visualize. The important point is that your exercise selections should be based on the integrated function of your body. However, you won't need to read through countless anatomy books and references since I'm going to break it down for you.
Before I move on, I have to lay to rest the misconception that you need to isolate key muscle groups so they'll grow and give you more "separation and definition" in that area. The abdominal region is a perfect example. My position is that you don't need to perform any "isolation" exercises for the abdominal region if you perform front squats, overhead lifts, deadlifts, and one-arm overhead presses. A few sets of reverse crunches or the ab wheel aren't going to hurt anything, but they're just not necessary for the vast majority.
It's been purported that you need direct abdominal exercises (crunches, twists, etc.) because you won't have muscle separation and definition in your midsection without them – even when your body fat is low. The proof, they say, is with marathon runners who have no significant abdominal separation even though their body fat might be as low as 6%.
That's an insanely stupid argument. Why? Because skinny marathon runners aren't doing heavy front squats, deadlifts, and overhead presses! You'd see some awesome abdominal development if the marathon runners in question would start doing those exercises. I always witness this effect whenever I put a former long distance runner on a muscle- building program replete with compound exercises.
You don't need isolation exercises for your midsection, period.
Okay, I feel better now. Let's move on.
Shaping a Muscle
You can't change the shape of a muscle.
It will grow, shrink or stay the same. You could do curls with your elbows tucked to your sides and a wide hand position until the cows come home and it won't do jack shit for the inner head of your biceps.
The reason? Because you can't fire the inner head without the outer head. Furthermore, show me one bodybuilder who got visible results with such unorthodox curls. In other words, targeting certain areas of your biceps looks great on paper, but it never pans out in the real world.
I do get a kick out of hearing the proponents of the curling variations with different arm and hand positions, though. Usually it goes something like this, "Most people perform curls with poor form (flared elbows) and their inner head gets neglected." Therefore they recommend targeting that lagging inner head by curling with your elbows in and hands wide.
Here's an idea: why don't you just start curling with better form?
Can you reshape a muscle? No. Can you train key muscles in a group to grow? No, unless it's the quadriceps. Since the quads are such a massive muscle group with four primary heads, and since each head is favored at certain knee angles, a little tweaking is possible.
For example, hack squats will build up your lateral thigh (vastus lateralis) because the movement overloads the vastus lateralis at knee angles greater than 90 degrees. The full, ass-to-grass front squat will build up your medial thigh (vastus medialis) because it overloads the vastus medialis at knee angles less than 90 degrees. But this is limited to the quadriceps. Indeed, it's the only muscle group that has the capacity to be fine-tuned.
It's true, if you think about it. How many times have you been in an argument where the naysayer in question referenced the quads as proof that you can reshape a muscle? A lot, I bet. How many times have you heard this same argument with the calves, biceps, glutes, or lats as proof?
Compounds In Rehab
You've probably already guessed that I'm a huge proponent of compound exercises over isolation exercises. Up until a few years ago, though, my position wasn't as extreme as it is now. That's probably because I used to perform many isolation exercises with my clients that needed physical rehabilitation.
One good example is the rotator cuff. If my client had a weak rotator cuff, I'd perform external rotation exercises with the upper arm resting on his knee. This insured that he could really "focus" on the external rotators because I didn't want any other muscles interfering with the movement. The results were fair.
Then I got into physical therapy research. (Luckily, I have friends like Bill Hartman, who helped hasten my way to the best of it.) With regard to the shoulder, it's been demonstrated that there's a strong link between shoulder instability on one side (right) and hip weakness on the other (left).
So now, all of my clients train their rotator cuff simultaneously with their opposite hip for at least one exercise. An example is the PNF diagonal with lunge as depicted in Hartman and Robertson's outstanding Inside/Out DVD. (Basically, this movement is a lunge with internal rotation, externally rotating as you return to the starting position).
They also train their external rotators with face pulls, but once again, it's a compound movement, not a crappy shoulder horn variation.
The same is true with virtually any other rehabilitation exercise I prescribe. Whether it's for the serratus anterior, gluteus medius, etc., my clients perform exercises that also engage the supporting muscle groups. There are some circumstances (as with lower traps) when it's difficult to train them effectively with compound movements, but for most muscle groups, it's not a problem at all.
Compounds Can Do It All
But this article isn't about physical therapy, per se. It's about building your size and strength as efficiently as possible. I can sympathize and empathize with those who want to build up a specific muscle group. There's nothing vain about wanting bigger muscles. But I hope you want those muscles to be able to perform well, too.
So here's an extensive list of exercises that will build up key muscles. The key muscles, of course, will be working with all of the other muscles that support their function. As you'll see, this isn't the usual "do squats for your thighs." I get very specific. The following movements are for bodybuilding purposes, physical rehabilitation is another article altogether.
Anterior tibialis (front calf)
Gastrocnemius/soleus (rear calf)
Vastus medialis (medial quads)
Full front squat
Single leg squat
High step up
Vastus lateralis (lateral quads)
Deadlift with narrow stance
Note: vastus intermedius and rectus femoris get plenty of work with theses moves, also.
Side step up
Deadlift with feet angled in slightly.
Good morning with feet angled in slightly
Biceps femoris (lateral hamstrings)
Deadlift with feet angled out slightly
Good Morning with feet angled out slightly
Deadlift (but only if you lock out at the top)
Front and Side Midsection
One-arm overhead dumbbell press
Dip with wide hand position
Push-up with feet elevated
Dip with narrow hand position
Close grip bench press
Partial military press (head to lockout)
Narrow grip pull-up with palms down
Narrow-grip row with palms down
Chin-up with palms up and neutral grips
Pull-up with a towel
Row with fat grip
Cable side raises
Lunge with external rotation
Neutral grip pull-up with wide grip
Neutral grip pull-up with shoulder-width grip
Pull-up with wide grip
Row with neutral (v-bar or rope) grip
Virtually any compound pulling movement
I have a lot of reasons for breaking down for correlating specific exercises with target muscle groups, even if intuitively it doesn't make sense. First, if you need to bring up a lagging muscle group, you need an effective list of exercises to choose from.
No need to do leg extensions for your medial quadriceps when a full front squat, single leg squat, or high box step up will build those muscles more quickly (along with developing healthier joints.
Second, it puts to rest many common misconceptions. For example, the good morning is a great exercise but it's not a great glute builder. The reason is because you can't fully lock out your hips at the top of the movement (the portion that emphasizes the glutes) without falling backwards.
Third, you'll develop much better structural balance and joint health if you stick to the recommended exercises. For example, I didn't mention the bench press for chest development. Is that because it's not a good chest builder? Of course not. It's because you typically can't get enough movement from the scapulae when you're doing it, and that makes it detrimental to shoulder health in the long run.
Focus on the push-up and the dip instead (make sure you "push" yourself as high as possible with the dip to activate your serratus anterior).
Again, this is not an exhaustive list to target every muscle in the body. I focused on the muscles that bodybuilders typically want to build for a more aesthetically balanced physique.
If you want to isolate muscle groups with machines, be my guest. But first ask yourself, "Is this how my body is designed to work?" If it's not, your strength and size results will always suffer.
Now you have the tools to revolt against any puny-ass isolation exercises!