Stable vs Unstable Surface Training – A Brief Word

Training is NOT Entertaining
Sometimes when I walk into a gym or private training facility, I look around and it looks like a rehearsal for the Ringling Brothers and Barnum and Bailey Circus. Trainers and their clients are standing on BOSU balls, juggling med balls, throwing Frisbees, counting backwards from 30, all while doing a lunge with a single-arm bicep curl.  Sounds ridiculous…because it is!  This kind of training gets “sold” or “marketed” by some trainers and Practitioners as “functional” training. While I acknowledge that unstable surface training does have its merits, particularly in orthopedic and neurological rehabilitation settings, and depending on the work or sporting environment in which one operates (skateboarding, surfing, etc.); to apply that model in traditional strength training with a population that is not ready for it (either due to physiological, biomechanical / kinesiological, or neurological reasons) is simply unintelligent and destructive.


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For the purposes of my discussion here, I would like to share the context of my use of the term “functional exercise.”   “Functional” to me means, “any exercise or activity in which the outcome matches the objective.” If the end result of your exercise/activity is exactly what you were hoping to get out of it, it can be deemed functional – to me.

What is the Goal?
Most people go to a gym or hire a “trainer” because they are looking for aesthetic changes. They simply want to look better naked – and I for one am all about this and appreciate anyone’s efforts to that end. They can have arms and legs that are falling off, disc pathologies in their necks and backs, migraine headaches 3 times per week, sleep disorders, and inevitably their number one goal is to lose weight (probably better stated that their number one goal is to improve body composition).

As I have mentioned in a previous post entitled Why Cardio Sucks, the best way to melt off unwanted body fat is to simply build and have more muscle. From this perspective, training on an unstable surface is likely detrimental to the primary objective of looking better “neked” and of resistance training which, in most settings, is to build strength, power, and/or increase lean body mass (LBM). Increasing strength and/or power typically requires that one produce a high level of intramuscular tension (IMT). IMT is proportional to the force being produced by the muscles and it is simply impossible to produce maximal force while being unstable. To quote Fred Hatfield, or perhaps someone who may have said this before Hatfield, “You cannot fire a cannon from a canoe!” 

So, if our goal is to look better in our birthday suit and we are trying to build more lean body mass, it is probably more “functional” to execute basic movements, such as squatting, lunging, dead lifting, etc., on the ground (a stable surface – yes, I know the Universe is still expanding and the planet is always moving but we can save that discussion for later) rather than trying to execute these movements on Swiss balls, wobble boards, BOSU balls, Dyna-discs, etc.  This way, we can achieve higher levels of IMT, have a better chance of overloading type IIb motor units (which have greater capacity for hypertrophy (growth)), and actually build some muscle, which will help us shed some of those unwanted pounds of body fat. If we choose to execute basic movements on unstable surfaces, we must recognize that the rate of force development and the stretch-shortening cycle are impaired, motor unit firing patterns and rate coding are altered, muscles are placed at a potentially dangerous biomechanical disadvantage, and you can easily create a favorable environment for injury. This does not exactly fit my definition of “functional.”


Executing sets of dumbbell bicep curls while lunging on a BOSU ball is not likely to help you look any better without any clothes on, or with clothes on for that matter.  One would be better served to simply execute lunges and bicep curls on the damn floor.



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Real World Application 

Let us attempt to better understand what I am speaking of through a real-world example:

We will use the bench press as our example exercise here. Say our client is a high school senior about to head off to college on a football scholarship to play the outside linebacker position. He is 6’2” tall and weighs 210 pounds. He is injury free and is in reasonably good health. He has a training age of 4 years and training experience has been a mix of free-weight training, Olympic lifting, and machine training. 

Q: Is the bench press a functional exercise for him? 
A: It depends.

If the objective of our client is to increase his body weight to 235 pounds in order to avoid being thrown around like a rag doll on the field, then the bench press can be one way by which we can increase his upper body and overall mass. So our answer here would be yes, the bench press is a “functional” exercise.  The outcome would match our objective.  Performing said bench press on a Swiss Ball does not make the exercise more “functional” just because it is an unstable surface.  The athlete will be far better off executing his barbell and dumbbell work on a bench.  


You are doing it wrong!  

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If this same athlete’s goal is to be able to improve his ability to push a load while standing, which is what he will have to do on a football field, then our answer is likely no, the bench press is not a “functional” exercise. The strength that he will develop while lying on his back on a nice comfortable bench that is fully supported, will not carry over very well into his sporting environment because the pattern that he has gained his strength in is too distant from the sport specific activity of pushing a load while standing. He would likely be better off training that push pattern from a standing position on a dual cable column. However, executing this bilateral cable push while standing on a wobble board is not likely to improve his performance on the field as it will decrease his force production capability in the exercise. 

In one scenario, the outcome of the bench press matches the objective and in the other it does not. This, from my perspective, is what determines how “functional” and exercise is – not how stable or unstable you are while performing it. Granted, if the trainee is a beginner with a training age of 0, and the extent of his athletic background is playing video games for 4 plus hours per day, then developing strength in the bench press very well may increase his ability to increase pushing strength in the standing position due to the fact that most of the initial strength gains in a beginner are due to improved nervous system activity and motor unit recruitment. 

To shift gears for a moment, if our client is a 38 year old stay-at-home soccer mom who wants to look better in a bikini and avoid injury while performing household duties and keeping up with the kids, unless she is performing her household duties and looking after the kids while on the Titanic, she stands a better chance of building some actual muscle and losing fat by executing her strength training exercises on the ground, on a bench, etc. – barring a pain syndrome due to muscle/structural imbalances, orthopedic, and/or neurological pathology of course.

It’s Not All Bad 
Having said all of the above, there are some cases where unstable surface training can be used at the same time as resistance training. For example, performing a split squat on a wobble board can improve the capacity to recruit the VMO. Some resistive unstable exercises can also contribute to improve the efficacy of the deep stabilizer system (inner unit) surrounding certain joints, etc. As well, certain athletes perform on unstable surfaces constantly and can be trained with resistance training in that environment, and as I mentioned earlier unstable surfaces are helpful in many orthopedic and neurological rehabilitation cases. Outside of these special cases however, it is of benefit to stick to the primary objective of resistance training: building strength and power and increasing lean body mass. If it (unstable surface training) is an adjunct to, and performed as a complementary component to a well designed training program and not as a substitute for some other integral training component, I feel unstable training can benefit athletic development. Should you continue to substitute back or front squats for squats standing on a wobble board or BOSU ball if you are trying to build muscle (and in turn burn fat) or develop relative or maximal strength? Absolutely not, for all of the reasons I mentioned earlier and more. 

What’s in the Tool Box? 
There is an old saying, “If all you have is a hammer, then everything looks like a nail.” I cannot remember who said that originally, but I love that quote. It is not my intention to bash unstable surface training – though I may have failed miserably there – I use it sparingly, but it has to be implemented at the right time, under the correct circumstances, with the appropriate client(s). To use it as a stand-alone training system is nothing short of foolish. To use anything as a stand-alone training system is foolish for that matter. Everything is a tool, and you must know what tool to use, how to use it – or what combination of tools to use – to get the best results (outcome matching the objectives). This is just one reason that thorough assessment of a client as well as a proper Needs Analysis of his/her work or sport involvement is a necessary component to Critical Program Design.

At the end of the day, if your goal is to improve body composition and look better naked – go lift heavy things on a stable surface!  My feeling is that the personal training industry sometimes underestimates how “functional” squats, deadlifts, chin ups, etc., really are, and gets caught up in “Swiss ball this”, “body blade and BOSU ball that” entertainment.     

I hope this post made some sense and has your “gears turning” a little bit. As usual, take what is useful to you and discard the rest. I typed this quickly off the top of my head, so my apologies if the thought process is not as refined as in previous posts.

Thanks for Reading,
Brandon J. Alleman


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