I cringe a little every time I see people in the gym lifting weights while sitting on a Swiss ball or doing squats balancing on a wobble board.
If you are not already familiar with them, exercise (or Swiss) balls, Dyna Discs, wobble boards, and BOSU balls are all types of instability devices that have been borrowed from physical therapists who use them to help their patients regain their strength and mobility as they recover from injuries.
The idea is that we strengthen our core by depriving it of a stable base. And whenever you add instability to any exercise, you increase the level of difficulty because your body works harder to stabilize your base.
This is the reason that pushups on a BOSU ball are more difficult than regular pushups. Or why lunges on a wobble board are far more challenging than lunges on the floor.
Unstable training can also help develop better overall balance and joint stability by strengthening the smaller stabilizer muscles around our back, hips, and joints. This improvement in strength and coordination not only helps improve the performance of elite athletes, but becomes increasingly important for all of us as we continue to age and become less active.
So if unstable training is so great, what’s the problem?
In our quest to achieve “functional fitness,” many of us have turned to using free weights, kettlebells, and suspension trainers such as TRX in order to better integrate our core muscles into our workouts.
We have been told that the best way to build our core strength is to add instability to our weight training routine. The only problem is that much like mixing cardio with weights when we end up combining core training with our traditional strength-building routines, we end up not doing either one of them as well.
The tradeoff of strength and power
In order to get stronger and increase the size of your muscles, you need to continually challenge them with heavier weights. When you lift weights on an exercise ball, you won’t be able to lift as much as you would on a more stable platform.
If your ultimate goal is to become stronger or build muscle, instability training is probably not the way to go because when you are on an unstable surface, you can not lift as much weight as you could if you were lying on a weight bench or standing on the floor.
Not only that, but one study found that, at least for competitive athletes, training on an unstable surface may actually undermine their performance because by “training slowly and tentatively, the athlete may be conditioned to perform in the same slow manner when faced with athletic challenges.” The reason why is that “antagonist [muscle] activity is heightened during [unstable training] to maintain joint stability.”
In other words, when you practice on an unstable surface, you are forced to slow down your movements in order to stabilize your joints, which ultimately reduces your speed and power.
This means is that no matter how much you may engage your core balancing on a wobble board, in the end lifting less weight or training your muscles to adapt to unstable conditions means building less strength, power, and muscle.
What is the goal?
When it comes to training for anything whether it is strength, speed, jumping ability, etc.… we have to remember that specificity is key. You always have to ask yourself what you are hoping to achieve and what’s the best way to get there?
This is the principle of specificity.
If we want to build our strength, we have to lift heavy weights
If we want to run faster, we have to do more sprinting
If we want to jump higher, we have to do more jumping
And if we want to improve our balance, we have to train specifically for that.
In other words, we can’t simply combine everything into a workout blender and expect that we’ll get the best of both worlds.
How to do an unstable training progression the right way
The way to develop your overall strength and use the concept of instability to your advantage is not by doing bench presses on an exercise ball or squats on a wobble board, but by gradually reducing the support of your core rather than the stability of your base.
Machines and free weights
Instead of doing bodyweight exercises, I typically suggest that people who are either new to weight training or have been away from it for a while start their training with the weight machines that fill most commercial gyms.
Machines have a fixed movement path that fit most (but not all) people and offer more support for your core and joint stabilization muscles.
Think of the difference between doing a seated shoulder press on a machine versus doing a standing barbell shoulder press and the different type of demands these two movements require when it comes to your back, core, and joint stabilization muscles.
Now think about doing the same standing shoulder press with dumbells raising one arm at a time. This movement requires additional core, back, and joint stabilization strength because of the unilateral movement.
One of the reasons that most people can lift more weight while doing a machine-assisted exercise versus doing the same exercise using free weights is because the machine is doing most of your body’s stabilization work for you.
Simply by moving from a machine-based exercise to a barbell, and to eventually using dumbbells, there is a natural progression of difficulty here, which along with specificity, is one of the core concepts of physical training.
Unstable training and bodyweight exercises
What instability training is good for is to strengthen your core and joint stabilization muscles.
Anyone who has tried them knows that planks and crunches become far more difficult when you are holding onto a wobble board or attempting to do a pushup with a TRX suspension trainer.
Balance training — same but different
Although they are often confused for one another and use similar equipment, unstable resistance training is not the same thing as balance training.
Where instability training often uses external resistance such as dumbbells, barbells, or kettlebells— balance training is typically bodyweight only.
Although the advantages of unstable resistance training are still being debated, the benefits of balance training have repeatedly shown to be useful for almost everyone from elite athletes to the elderly.
Where balance training really shines is its ability to improve ankle and knee proprioception, because it not only helps to refine your sense of balance but also increases stability around these crucial joints.
Proprioception is the body’s awareness of itself in space and how it is moving, while balance and stability is the body’s ability to maintain a particular position in that space.
In other words, proprioception is knowing what your body is doing, while balance is the ability to react to those changes. This is why balance training not only improves performance and prevents injuries in athletes, but becomes increasingly important as we age to help prevent falls.
Separating balance and strength training
Just because strength training and balance training are both good things, that doesn’t necessarily mean they should be done together. We tell ourselves that by combining them, we are making our workout more efficient, but the research says that we would be better off separating them.
Bodyweight balance training should ideally be done either on separate days from your resistance strength workout and/or used as a brief warm-up beforehand as a way to activate your joint stabilization muscles.
Keep in mind, however, that because most of these stabilization muscles are relatively small, there is a risk of exhausting them if you work them too hard or for too long during your warm-up. So be sure to keep it short.
Unstable exercises are a concept that has been borrowed from physical therapists to help rehabilitate injuries and improve the body’s balance and proprioception.
Although balance training and unstable resistance workouts use similar equipment, they should not be confused for one another.
While the overall effectiveness and safety of using instability devices when training with barbells, kettlebells, or dumbbells is still being debated in the sports research community, the benefits of bodyweight balance training are clear.
In other words, save the wobble boards and exercise balls for isolated core and balance work or even as a quick warm-up. However, don’t go overboard here, because there is a risk of overworking these small stabilization muscles before you even begin your strength training workout.
Behm, D. G., & Anderson, K. G. (2006). The role of instability with resistance training. J Strength Cond Res, 20(3), 716-722.
Cuğ, M., et al. (2012). The effect of instability training on knee joint proprioception and core strength. J Sports Sci Med, 11(3), 468-474.
Mettler, A., et al. (2015). Balance training and center-of-pressure location in participants with chronic ankle instability. J Athl Train, 50(4), 343-349.
Behm, D. G., et al. (2010). Canadian Society for Exercise Physiology position stand: The use of instability to train the core in athletic and nonathletic conditioning. Appl Physiol Nutr Metab, 35(1), 109-112.
Cressey, E. M., et al. (2007). The effects of ten weeks of lower-body unstable surface training on markers of athletic performance. J Strength Cond Res, 21(2), 561-567.
Uribe, B. P., et al. (2010). Muscle activation when performing the chest press and shoulder press on a stable bench vs. a Swiss ball. J Strength Cond Res, 24(4), 1028-1033.