It is often said that variety is the spice of life, and unfortunately for the uneducated masses, this platitude has permeated into the world of exercise and fitness. One of the largest problems I see in exercise programs today is by far too much variation. I admit that I am often guilty of this myself. As someone dedicated to lifting for the long haul, and as a self-proclaimed eschewer of all things normal, I am constantly tuned into new exercises and loading patterns to maximize efficiency in the gym. The normies out there who like eating chips and watching Glee do not enjoy exercise; I do. I enjoy it for its intrinsic nature, I like to experiment with new movements and exercises purely for the fun of it. This can lead to the same lack of consistency in programming that is seen in programs for newbies and intermediates.
Variation and progressive resistance have their logical place in an exercise routine, but they absolutely must go hand in hand. Variation CANNOT take place in an exercise routine until the adaptation has been made. It is constantly harped from the heavens that we must ‘switch up our routines’ but the truth of the matter is, that most people switch things up too often and in the wrong direction. Exercise causes the stimulus, our bodies recover and adapt, to be followed by another stimulus, and progress continues. Our General Adaptation Syndrome principle explains this quite clearly. It is important to remember that our bodies do not adapt because we want them to, they adapt because they have to. Adding muscle and decreasing body fat means that the body will have to increase the metabolism and expend more calories throughout the day, and have less energy available in storage form should the apocalypse descend upon us. Our bodies want to avoid this. (A change from homeostasis, not the apocalypse.)
Your body does not care if you worked real hard on your last set of curls, it will only adapt if it has to. In order to adapt we must have an adequate stimulus, followed by adequate recovery, AND REPETITION OF THIS STIMULUS. We do not adapt significantly to an isolated incidence. The example I use with my clients is this: say you carry in the groceries one night, say they’re really heavy. Say getting those damn groceries in the house is as hard as any Farmer’s Walk workout you’ve ever done. This is most certainly a stimulus to the body, but say you don’t need to do this activity again for a month. Any possibility for growth from this exercise is now gone because the recovery period was significant enough to prevent any adaptation. Nothing happens. You do not get stronger, you do not lose body fat, and you do not improve your conditioning. Nothing. Now say that you love carrying groceries so much that you want to make it a living. You now carry groceries for 8 hours a day for everyone in the neighborhood. Now does your body make an adaptation? You’re damn right it does. So what’s the difference? The difference is repetition of the stimulus. The body is stressed, it recovers, and there is a further stress followed by further recovery setting off all kinds of signals in the body that SOMETHING HAS TO CHANGE. This is how exercise changes how we look, feel, act, and do the horizontal mambo. Your muscles don’t get confused. They either squeeze or they don’t. The only difference in terms of loading patterns is how to stimulate the largest portion of motor units through loading, repetition, and variation.
Crap there’s that word again. But here in lies the rub. The variation only takes place AFTER the body has adapted to the previous stimulus, and is a furtherance of the adaptations made in previous cycles. That means that the exercise can change, but the loading/stimulus of the exercise is such that progress is continued by demanding more motor units and subsequently more activation of the fibers. Different for the sake of different is pointless with regards to training. Masturbating with your left hand does not improve how you masturbate with your right, and you are still not moving on to bigger and better methods of busting out the baby batter. Incorporate variation in programming certainly, but with three caveats in mind: What have you just done, what are you about to do, and where are you going.
There has been much discussion recently concerning exercise variation, and I think several questions about the topic need to be answered before we can make an adequate appraisal of an exercise. Once we know that an adaptation has been made to its fullest extent, and we now want to switch up exercises, we need to be certain that this next exercise will help us achieve our goals rather than the dreaded ‘different for the sake of different’ mentality. There are several questions we need to get a handle on to evaluate an exercise. For the sake of argument let’s analyze further the argument of the superiority of either a bilateral or a unilateral movement.
First in order to say that an exercise is ‘superior’ we must beg the question of superior in what way? What are the distinguishing criteria of a superior exercise? What does an exercise seek to develop and what is its level of effectiveness at developing this quality? This is also a major theme often overlooked in beginner and intermediate programs. I teach at the National Personal Training Institute in Northern Virginia. I will often hear my newbie students chime in with such gems as ‘oh yea that’s a great exercise’ when talking about a Russian twist to a deadlift to anything in between, and my immediate question to them is ‘great for what?’ What is it about a particular exercise that makes it great? What qualities does it develop and does it develop these qualities faster or more efficiently than other exercises that develop the same qualities. I am usually met with a blank stare following this question. Most people do not delve into the issue this extra step, and we must in order to determine a proper exercise protocol. Here is my opinion on the issue. (I also realize that this is merely an opinion, as it is based purely on logic, rather than scientific data). An effective exercise develops as many physical qualities as possible so that these characteristics can be expressed in other movements. According to this logic, if doing a Max Effort Accommodated Resistance Explosive Flexibility Jumping Jack was proven to improve absolute strength, relative strength, flexibility, power production, lean mass, sex appeal, intelligence, sun tan and all other physical qualities, than obviously it should become the bulk of your program.
If we imagine the very first caveman to even invent the term exercise, we would realize that the only point in performing an exercise is to become better at other movements. Our caveman wants to get better with his spear, so he practices throwing the spear, then eventually throwing heavier spears, then eventually throwing rocks, but all with the goal in mind of improving his spear throwing. If doing sit ups on the back of a brontosaurus does not improve his ability to throw his spear IT IS A WORTHLESS EXERCISE as far as his goals are concerned. This is the difference between an exercise and an activity. An activity can display certain physical characteristics, but an exercise actually develops them. It was explained to me years ago by Louie Simmons, in the concept of Builders and Testers. Certain movements are great as a display of strength, athleticism, balance etc., and others build and improve these qualities. Example: ripping a phone book in half is a great display of strength, but if you wanted to get strong you wouldn’t necessarily shred every phone book on the block until you were standing on a heap the size of my weekend dumps. You would build hand strength through the most effective means of hand strength development, then apply your newfound strength to the art of phone book ripping.
Now this is where specificity of movement comes in. If you compete in something specific, you’re going to want to practice the activity in and of itself, but the goal is to ALSO incorporate other movements and exercises to then carry over to your performance. This is why riding around on your bike in spandex doesn’t make you an athlete. A real athlete would eat all the dog crap out of the yard if it could legitimately improve their performance. A real athlete will do whatever is necessary to improve performance, including things that are hard like lifting weights and pushing Prowlers. There is more to it than just playing your sport or activity.
So allow us to be a bit bold, and apply this logic to a complex issue as compared with a simple one. Our friends the wussy, functional training unilateral guys, and the meat-head moron bilateral army both contend that their style of exercise is superior. Let us use the transfer of physical qualities to other movements as our measuring stick. Now we must determine exactly what qualities we are trying to improve. Are we trying to improve muscle mass, strength or athleticism? As despite what popular opinion would imply, these are not the same thing. If they were, Mr. Olympia would win the powerlifting world championships every year and win the NFL MVP for playing all 11 positions simultaneously. Therefore right off the bat, we must make a distinction, these movements by their very nature will be performed and executed differently which WILL STRESS DIFFERENT QUALITIES AND IMPROVE DIFFERENT QUALITIES. One may be superior for strength development and another for balance and coordination (let’s call it athleticism). We cannot logically compare them when we are using different criteria in their assessment.
Now if we are going to compare different movements, we must know whether or not they are similar enough to be comparable to the extent that the existence of one movement in a program would elicit the expulsion of a redundant movement. Example: if squats and split squats do the exact same thing, performing both would be redundant and just a waste of our valuable left handed jerk off time. According to this logic, to compare a Squat with a pistol squat, and a single leg deadlift to a conventional deadlift does not make much sense. Biomechanically these movements are not as similar as they would seem. A single leg deadlift requires forcing one leg back, which can be used as a counter balance. Using a barbell vs. dumbbells vs. a weight vest changes the loading pattern, and therefore EVERY LEVER ARM of the exercise. The lever arm is what is stressed to move the weight. If this changes, the entire exercise changes as well.
This is why a low bar squat is easier than a high bar squat. This has nothing to do with your muscles, this is biomechanics. To be compared as exercises the single and double leg varieties would have to have the same lever arms participating in exerting force on the load. This same phenomenon can be seen in the Back Squat vs. pistol. If they are measuring different qualities and using different biomechanical patterns, of course we will see different results. This is why guys who squat a grand can’t always do a pistol, and guys who bang out an easy set of ten pistols can’t always squat 315.
So now we have begged another question. If there is a discrepancy in the performance of a unilateral vs. bilateral exercise in the same individual, what causes this? There must be some trait or quality that an exercise tests that the individual does not possess. Logically, not physiologically, the answer is simple.
Guys who can do unilateral movements with their requisite lighter loads, are just not strong enough to express strength thru bilateral movements. 10 pistols at a bodyweight of 200 lbs. but can’t squat 400? Not strong enough. Not rocket science here. This could be for a number of reasons. This is certainly due to the exercises performed before this point. Either effective exercises have been used to an ineffectual degree, or inappropriate exercises have been performed.
So what causes the discrepancy in the performance of these exercises across motor patterns of one individual? (To compare more than one person would complicate the issue to the extent that any arguments would be circuitous, so the fact that your buddy so and so can squat or pistol well becomes irrelevant unless we compare his exercises to himself.) Obviously the biomechanics are different, but it is also apparent that balance and coordination are required in both types of movements. We can all agree that unilateral movements require more balance and coordination than bilateral movements. Therefore we have made an important distinction. Is the level of balance required for a unilateral movement sufficient that strength cannot be expressed even in one strong enough to display it? So if Donny Thompson can’t do a pistol (he may be able to, this is merely an example) is it because he cannot fire enough motor units or because he lacks the balance, flexibility and coordination to perform a movement which is NOT biomechanically similar to his world record back squat?
So now let’s reverse the issue. We have an individual who can single leg RDL the same as his conventional deadlift, again merely for the sake of argument. It would seem that his balance and coordination is not the limiting factor here, it would be his strength. So if balance and coordination is the limiting factor in unilateral movements, then this is what is being tested with these particular exercises (whether they build these qualities is an issue I will leave well enough alone). Then we have now also established that strength is the limiting issue in a bilateral movement, provided balance and coordination are developed to such an extent as to allow maximum force production.
So let us take a step back for a moment. Remember 100 pages ago that we first had to determine what it is we were trying to develop? Let’s look logically at how unilateral compares to bilateral with regards to strength development. When developing strength, the total load matters. Our SAID principle of specific adaptations to imposed demands tells us real easy that if we want to get strong we have to lift heavy; if we want to run fast we have to run fast. Basic. So if strength is the goal of an exercise, we must take a look at the total load to the muscular system of that exercise. This means that single leg deadlifting 275 for 5 off one leg and conventional deadlifting 550 for 5 off two legs cannot be the same thing. 275 for 5 off one leg requires TWO sets to hit each leg. So now we have an issue. We have a load of 275 held in two hands, and moved with the entire trunk, with only one leg removed. The trunk, upper body, and nervous system are stimulated to the tune of 275 for two sets, whereas to deadlift 550 for 5 means that the trunk, upper body, both legs, and nervous system are stimulated to the tune of 550. To argue that they are similar is to argue that a set of 10 is more effective than a set of 5 with regards to the nervous system. Decades of research has demonstrated that the load in a particular exercise can be paramount to the stress adaptations caused by the lift. If a guy does a set of leg extensions, leg curls, ab wheel rollouts and hyper extensions, we do not total the loads of all of these exercises and say that the total poundage is higher than the squat and these exercises are therefore superior for strength development. Not by a long shot. The total load of an INDIVIDUAL set has to be accounted for and is our criteria for measurement provided that the comparable exercises share the same biomechanical patterns, lever arm lengths, and range of motion, which is a huge thing to take for granted given our earlier discussions. Even if the total of both legs on a unilateral exercise is higher than the load for a bilateral movement, the total load to the system is always higher with the bilateral movement. My conclusion: Bilateral for strength development in order to maximize the efficiency of the nervous system of an individual set.
So now we must flip the coin with regards to training for athletes. It should be clear that there is more going on than pure strength in athletics (a tough concession to make for a former strength coach). We also have to be specific to the motor patterns involved in a given activity so that our exercises improve the performance. If your sport involves running, cutting, and dicing up a defense occasionally on one leg at a time, then it would make sense to incorporate these movements into a proper program. If your sport consists mainly of bilateral movements, then that should be the only argument necessary for prioritizing these movements in training. So in designing a program for an athlete, it would make sense to incorporate bilateral movements for strength, and accessory unilateral movements for balance, and coordination. Both are necessary for sport, but which should be prioritized depends upon the athlete. By looking at both bilateral movements and unilateral movements with a particular athlete we should be able to determine where our deficiency lies. A bilateral deficiency will be seen where strength is the limiting factor and a unilateral deficit will be seen where balance and coordination are limiting. Based on this weakness, we then have the objective necessary for an effective program.
We should also mention the speed of development of particular qualities. Balance and coordination will develop much faster than strength will. I can teach Donny Thompson how to do a pistol, long before you can teach Johnny-Pistols-A-Lot how to deadlift 500lbs (obviously provided that they can’t already). Strength takes a long time to develop as we all know, but more importantly technique is merely an extension of strength. Technique (another way of saying balance and coordination) can only be expressed in the presence of adequate strength. If someone is not strong enough to squat their bodyweight, you can yell ‘Knees Out!’ at them until you’re blue in the face, but it still ain’t happening. Strength has to be there in adequate quantities before technique can be expressed, and will therefore develop much faster. Logically speaking.
So now at long last after your eyes have fallen out of your head, I can summarize a bit. First- With regards to strength development, total loading is our measuring stick, and should be maximized during a SINGLE SET. Second- if balance, coordination, and sport specificity are desired a change of the biomechanics of the motor pattern may be desired; meaning that we would elect a unilateral movement over a bilateral movement. Third- Unilateral and Bilateral movements (at least their body weight varieties) are so biomechanically different, as to no longer demonstrate efficient comparison.
So which exercises do you pick? You pick the exercise that has the greatest benefit depending upon your goals by thinking analytically and logically about your choices. So do whatever you want. But you better have a good reason.
Elliott White has worked in the Strength and Conditioning field at the collegiate, professional, and private levels. He is currently the Director of Personal Training at Fitness First in Tysons Corner VA, and an instructor with the National Personal Training Institute. He holds a MS of Exercise Science, has been certified with the NSCA, USAW, FMS, TAKB, and is a competitive powerlifter (2617)