It’s an age old argument. “Are Compound Exercises better than Isolation Exercises?”. There are many who believe that a particular group of exercises known as “Compound” (Squats, Bench Presses, Overhead Presses, Power Cleans, Dead Lifts, Parallel Bar Dips and Bent Over Barbell Row) are essential for everyone – regardless of their goal. However, as we’ll soon see, that recommendation is misguided.
Let’s begin by defining what these two terms mean – “Compound” and “Isolation.” The generally-agreed-upon definition of a “Compound Exercise” is one which involves more than one muscle and more than one joint, simultaneously. Conversely, the generally-agreed-upon definition of an “Isolation Exercise” is one which involves only one muscle, and only one joint. So, by these definitions, a “Bench Press” would be a Compound Exercise because it involves the Pectorals, the Anterior Deltoids and the Triceps, along with two joints (the shoulders and the elbows). The “Standing Barbell Curl” would be an Isolation Exercise because it involves only the Biceps, and only one joint (the elbow).
The first “problem” which arises from this definition, is that is attempts to lump all exercises into either one group or the other. Then, it attempts to deem all of the exercises that are in group as “good”, and all the exercises that are in the other group as “bad”. Both of these notions are mistaken. In fact, all exercises are “compound” exercises to varying degrees. For example, the “Standing Barbell Curl” involves more than simply the Biceps and the elbow. If it were not for the participation of the Erector spinae (muscles which support the spine, from the pelvis all the way up to the neck), the weight of the barbell would pull the torso forward. Also, were it not for the static tension of the Glutes and the Hamstrings, and the stabilizing force of the Trapezius, the person would be unable to perform the exercise. There is also participation from the forearm muscles and the muscles of the hand and fingers, as well as of calves and feet.
Ironically, proponents of “Compound Exercise” might try to disregard the static stabilization of the participating muscles during a “Standing Barbell Curl”. Yet, they’ll defend the Plank as being a “Compound Exercise”. Ironically, the Plank is an exercise which is entirely static, with no movement whatsoever. So, calling the “Plank” a “Compound Exercise” is to acknowledge the participation of stabilizing muscles. In essence, the “Standing Barbell Curl” is like a Push-Up (another exercise that is deemed “compound”), in the sense that some muscles are working isometrically while others are working dynamically. Therefore, regarding the ‘Standing Barbell Curl” as an “Isolation” exercise is simply incorrect.
Here’s another irony. Proponents of “Compound Exercise” usually dismiss the involvement of the Erector Spinae, during a “Standing Barbell Curl”, as MERELY “stabilizers”. Yet, they’ll suggest that the “stabilizing” effect of the abdominal muscle during a Hanging Leg Raise is sufficient to designate that exercise as an “Abdominal Exercise”. Why don’t they call the “Standing Barbell Curl” a “lower back exercise”? In fact, the Hip Flexor muscles work as hard during a Hanging Leg Raise, as do the Biceps during a Standing Barbell Curl. But they don’t regard the “Hanging Leg Raise” as primarily a “hip flexor exercise”. Clearly, these definitions are failing us.
Peripheral Recruitment PERIPHERAL RECRUITMENT
Virtually every single exercise imaginable involves more than one muscle, and more than one joint. This includes exercises that involve a combination of dynamic and isometric contractions (like “Standing Barbell Curls”) and exercises that are entirely “static” (like “Planks”). Rarely, if ever, is there only one muscle involved in an exercise. For this reason, I coined the term “Peripheral Recruitment” – which refers to the “engagement of muscles and joints that are peripheral to the target muscle”.
All exercises have varying degrees of “peripheral recruitment”, and each part (muscle and/or joint) of an exercise’s peripheral recruitment has its own, unique potential benefits or consequences, depending on the various bio-mechanical factors of a particular exercise. It is wrong to automatically assume that every part of a compound exercise’s peripheral recruitment is “good”. Often times, certain aspects of a compound exercise present a disadvantage, a consequence or a injury risk.
EXAMPLE: “Bent Over Barbell Row”
Although this particular exercise is not commonly seen in gyms as much today as it was in years gone before, it serves as an extreme example of what happens frequently in other exercises today. Let us begin by first acknowledging that this has been designated as an “upper back” exercise. It was used for the purpose of “developing the Lats and upper back muscles”, and some traditionalists still believe it to be a “foundational” exercise.
The Trapezius begins on the spine, and attaches onto the scapula (i.e., shoulder blade). It does NOT connect to the arms at all. Therefore, the Traps do not pull the arms downward during a Lat Pulldown, nor do they pull the arms backward during a Rowing exercise. Their only function is to pull the scapula backward.
While we are in the “Bent Over Row” position, we are significantly loading the lower back muscles (“erector spinae”), even though that is not our target muscle. In fact, we are risking injury to our spine, especially if we allow our back to be rounded while bent over and loaded. We are also loading the gluteus muscle and the hamstrings, although isometrically (likewise, the erector spinae). So, although these muscles are “working”, they are not necessarily working with the same degree of productiveness that they would be if they were working dynamically (with full range of motion). This constitutes effort that is largely “wasted”. It’s energy spent, that does not produce a visible result in these muscles.
The rear deltoids are also working – even though they are not muscles of “upper back”. They are also not working through their ideal range of motion (not enough at the beginning, and too much at the end). It could be said that they are benefitting more than the lower back, glutes and hamstrings, although not as well as they could benefit if they were working in a dedicated “rear deltoid exercise”. Further, this movement does not eliminate the need to do a dedicated “rear deltoid exercise”. So, in essence, it’s extra work – but not necessary work – for the rear deltoids. Assuming we’ve already taken care of working our Lats and Teres major by doing Pulldowns or Chins (or my preferred “Lat Pull-Ins”), that leaves the other muscles shown above.
Neither the Infraspinatus (which ONLY rotates the upper arm bone) nor the Trapezius (which ONLY pulls the scapula back) pull on the arms during a any kind of Rowing exercise. The Infrapinatus only rotates the arm externally (there is no humeral rotation during a rowing exercise), and the Trapezius is not even connected to the arms.
So….the Bent Over Barbell Row “wastes” a bunch of energy using (and straining) the lower back, the glutes, the hamstrings and the rear deltoids, while only getting some benefit to the TRAPS from the pulling back on the shoulders at the top of the Rowing movement. The Lats also get a small amount of benefit from Rows, but much less than they do from Pulldowns. So, what’s the assessment of the “Bent Over Barbell Row” ? It’s like paying $100 of cost, and only getting about $15 of benefit (to the “upper back” muscles). That is NOT good return on your investment of time and energy.
Clearly, at least SOME “compound” exercises are not necessarily good.
A MORE SIMPLIFIED ANALYSIS
Given the time it takes to analyze every aspect of an exercise (like the one above), I’ll spare you the detailed analysis of other sample exercises. However, be assured, every exercise can be analyzed this way. And should be analyzed – perhaps not in the way I’ve done so here… but at least from a general, common sense perspective. A simple way might be like this. Take the “Hanging Leg Raise”, for instance. You are asked to hang my your fingers and arms on a chinning bar, and raise your legs (or knees, at least), forward and upward. And you believe this is for the benefit of your “Abs”.
First, you should acknowledge that your fingers and arms have nothing to do with your Abs. So that energy (and strain) is entirely unproductive to your goal of working your abs. (Note: I’ve seen some people doing this while hanging from ONE arm, as if hanging from two arms wasn’t already foolish enough.)
Secondly, the Abs do not connect to the legs. So, whatever muscle is pulling your legs forward and upward, is benefitting MORE than your Abs. That muscle(s) is the “hip flexors” (technically, the Iliac and the Psoas, known collectively as the “Iliopsoas”). These are not muscles that can be seen (they are many layers deep), nor muscles which are important to keep strong. So, exercising them is not vital, and potentially distracts from your goal of working your Abs.
The participation of the Abs, during a “Hanging Leg Raise”, is almost incidental. Your abs essentially keep the spine steady, while all the other muscles listed above work harder than the Abs do. Again, you’d be spending $100 of “effort”, but only getting about 5% benefit to the Abs. You’d be MUCH better off doing regular Ab Crunches on a floor mat.
By the way, there is no “lower abs”. It’s impossible to “spot reduce” any area of your body, and it’s impossible to ad ridges to your “four pack”, or your “six pack”. “Ridges” of the abs (technically called “tendinous intersections”) are determined by genetics, and are there (or not there) from birth. No exercise in the world can add a “tendinous intersection” to your abs. Stop trying to work your “lower abs” – especially by doing foolish exercises like “Leg Raises” (of ANY kind). They’re not worth doing at all.
Rather than thinking of exercises as either “Compound” or “Isolation”, we should consider all exercises as “shades of gray”. All exercises have varying degrees of Peripheral Recruitment, and it’s not always “advantageous”. When we do Upright Rows, our wrists are turned sideways. This is very uncomfortable, and distracting. It’s a “weak link” that does not make the exercise any more productive.
When we do Barbell Squats, the load on the lower back (based on an individual’s structure) may be excessive. Further, the external rotation of the humerus (shoulder joint), which occurs when holding the barbell (during Barbell Squats) as it sits on our shoulders, might be painful for a person. These peripheral recruitments might be weak links when doing Squats. If they present enough of a distraction, discomfort, pain or weakness, the standard Barbell Squat may not be a good option for this particular person. During all exercises, we should evaluate whether or not the peripheral recruitment of assisting muscles, and participating joints, interferes with the maximal loading and fatiguing of a target muscle. We should not assume that all “compound exercises” are good, nor that we “should” do them, or else we’ll be at a disadvantage.
There is no special benefit to a muscle that is working during a “Compound Exercise”, as one of several participating muscles during that exercise – compared with being the only muscle working during an “Isolation Exercise”. Muscles don’t “know” nor “care” whether their neighboring muscle is also working, along with them, during an exercise. Muscles do the one and only thing they can do, which is to contract and move the joint between their origin and insertion. Whether they work alone, or in conjunction with other muscles simultaneously, is irrelevant. If one’s primary goal is to save time – at the expense of maximal gains – then doing only “Compound Exercises” (i.e., exercises that involves more than one muscle at a time) might be a somewhat reasonable choice. But it’s not an ideal strategy for those who want maximum benefit.
Ultimately, I believe we should do away with the terms “Compound” and “Isolation” exercises – knowing that all exercises have a degree of “compound” in them. All exercises have varying degrees of peripheral recruitment. Sometimes that recruitment is acceptable, and sometimes it’s detrimental. It’s up to us to determine if we are able to maximally work a target muscle, or if some weak link (or multiple weak links) interferes with that objective.
About the Author
Doug Brignole is a veteran competitive bodybuilder, currently in his 38th year of competition. Having started at the age of 16, and winning numerous teenage competitions in addition to the Overall Mr. California, and his weight division in Mr. America and Mr. Universe, Doug now has his sights set the World Championship of 2014. He has been an enthusiastic student of biomechanics for many years, writes for a number of websites and magazines, and is now working on his second book. He has been certified by the American College of Sports Medicine and the American Council on Exercise.