Unstable Surface Training

Posted: November 8, 2010 in Misc., Training
Tags: , , , ,

Despite it’s popularity, unstable surface training makes people weaker and slower, and actually activates LESS muscle fibers than doing the same exercises in a stable environment, “core” or otherwise. There’s quite a bit of research on this subject; I’ve just included a few examples below.

J Strength Cond Res. 2010 Feb;24(2):313-21.

Muscle activation patterns while lifting stable and unstable loads on stable and unstable surfaces.

In an attempt to mimic everyday activities that are performed in 3-dimensional environments, exercise programs have been designed to integrate training of the trunk muscles with training of the extremities. Many believe that the most effective way to recruit the core stabilizing muscles is to execute traditional exercise movements on unstable surfaces. However, physical activity is rarely performed with a stable load on an unstable surface; usually, the surface is stable, and the external resistance is not. The purpose of this study was to evaluate muscle activity of the prime movers and core stabilizers while lifting stable and unstable loads on stable and unstable surfaces during the seated overhead shoulder press exercise. Thirty resistance-trained subjects performed the shoulder press exercise for 3 sets of 3 repetitions under 2 load (barbell and dumbbell) and 2 surface (exercise bench and Swiss ball) conditions at a 10 repetition maximum relative intensity. Surface electromyography (EMG) measured muscle activity for 8 muscles (anterior deltoid, middle deltoid, trapezius, triceps brachii, rectus abdominis, external obliques, and upper and lower erector spinae). The average root mean square of the EMG signal was calculated for each condition. The results showed that as the instability of the exercise condition increased, the external load decreased. Triceps activation increased with external resistance, where the barbell/bench condition had the greatest EMG activation and the dumbbell/Swiss ball condition had the least. The upper erector spinae had greater muscle activation when performing the barbell presses on the Swiss ball vs. the bench. The findings provide little support for training with a lighter load using unstable loads or unstable surfaces.

Marc’s Comment: Of eight muscles EMG tested during overhead pressing (barbell and dumbbell, on a bench or a swiss ball), only the upper erector spinae showed increased activity when done on an unstable surface. Meaning that almost 90% of the muscles used during this exercise (“core” and prime movers) were more active during stable surface lifting.


J Strength Cond Res. 2010 Oct;24(10):2723-30.

Deadlift muscle force and activation under stable and unstable conditions.

The objective of this study was to compare the production of force and paraspinal muscle activity between deadlifts carried out in a standard way and with different instability devices (Bosu and T-Bow). Deadlifts involve the performance of muscle activities with dynamic and isometric characteristics. Thirty-one subjects participated voluntarily in the study. Initially, they performed an isometric test for 5 seconds in each condition. After that, they performed a set of 5 repetitions with 70% of the maximum isometric force obtained in each one of the previously evaluated conditions. During the isometric tests, records of electromyographic activity and force production were obtained, whereas during the dynamic tests, only the electromyographic activity was registered. The subjects produced more force and muscle activity on the stable surface than under the other conditions during the isometric test (p < 0.05), and the same differences in muscle activity were observed during the dynamic test (p < 0.05). These data show that the performance of deadlifts under stable conditions favors a higher production of maximum strength and muscle activity. Therefore, we conclude that the use of instability devices in deadlift training does not increase performance, nor does it provide greater activation of the paraspinal muscles, leading us to question their value in the performance of other types of exercises.

PMID: 20885194

Marc’s Comment: Deadlifting on an unstable surface caused less muscle activity and less force production. Good way to get weaker and slower.


Appl Physiol Nutr Metab. 2010 Feb;35(1):109-12.

The use of instability devices and exercises to train the core musculature is an essential feature of many training centres and programs. It was the intent of this position stand to provide recommendations regarding the role of instability in resistance training programs designed to train the core musculature. The core is defined as the axial skeleton and all soft tissues with a proximal attachment originating on the axial skeleton, regardless of whether the soft tissue terminates on the axial or appendicular skeleton. Core stability can be achieved with a combination of muscle activation and intra-abdominal pressure. Abdominal bracing has been shown to be more effective than abdominal hollowing in optimizing spinal stability. When similar exercises are performed, core and limb muscle activation are reported to be higher under unstable conditions than under stable conditions. However, core muscle activation that is similar to or higher than that achieved in unstable conditions can also be achieved with ground-based free-weight exercises, such as Olympic lifts, squats, and dead lifts. Since the addition of unstable bases to resistance exercises can decrease force, power, velocity, and range of motion, they are not recommended as the primary training mode for athletic conditioning. However, the high muscle activation with the use of lower loads associated with instability resistance training suggests they can play an important role within a periodized training schedule, in rehabilitation programs, and for nonathletic individuals who prefer not to use ground-based free weights to achieve musculoskeletal health benefits.

PMID: 20130673

Marc’s Comment: Please take note of the first bolded sentence. If you’re recommending “drawing in” of the belly button, realize that you’re solidifying your irrelevance. I’d recommend reading Stuart McGill for more information on the subject. Some of the conclusions in this paper were solid, others not as much.



Increased stability and proprioception can be effectively achieved on solid ground. The “core” will be activated far more effectively during execution of deadlifts, squats, presses, rows, cleans, etc than any sort of balancing act. A trainee requiring more stability work for whatever reason can easily achieve this through unilateral work (king deadlifts, RDL’s, pistol squats, split squats, lunges & step ups (incline, decline, side, angled, etc). There’s hundreds of ways to perform exercises to increase stability without inflatable toys.

  1. John Stone says:

    I think a whole post could be dedicated to your final comment about hollowing versus bracing. Learning how to use those muscles is such an interesting endeavor and all together so essential if you’re training is focused on movements like squats, dead lifts, getting out of bed in the morning, throwing away the garbage, reaching down to pick up your girlfriend’s toy chihuahua.

  2. Trudi says:

    Its not my first time to go too see this web site, i aam visiting this website dailly and take fastidious facts from
    here all the time.

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