In our previous article, we busted some myths around the usage of the term “functional training”, and often the efficiency of the “training” involved is sacrificed for the “fun”. That was just a warm-up. Let’s now move on to another type of training trend that is hard to ignore - Unstable Training. Walk into a gym, and you will most likely find a variety of balance apparatus stacked neatly on a rack or strewn around the “functional” area.
Unstable surface training directly translates to exercising on surfaces that don’t stay still - usually on something like an exercise ball or a bosu ball. People who tend to gravitate towards this type of training are often coordinated but not particularly strong, proposing instability and functionality as a justification for their choice of preferred training methodology.
Let’s get a little technical here. Performing a movement that decreases the stability of an exercise will lead to a reduction in force output ; simply as a result of how the body functions - when more coordination is required to perform a movement, the body downregulates force.
The neurotransmitters required for coordination (acetylcholine) and maximal force output (dopamine) are quite different. It has been shown that dopamine inhibits the release of acetylcholine (ACh) from nerve terminals of caudate cholinergic interneurons. Basically it is difficult to exert maximum effort when you are simultaneously attempting to maintain balance.
Imagine if your joint is unstable due to ligament damage - maybe because the motor coordination to the joint is insufficient to control load distribution, or you are experiencing pain due to cartilage damage in the joint - it would not make sense for your body to allow maximum force output from the muscles controlling the joint.
The same sensory logic boils down to the fact when one trains on a surface that is unstable or with a weight that has an unstable centre of mass. The output WILL accordingly decrease.
There is also a misconceived perception with respect to what muscles are doing in stable conditions. People tend to view it as an idle state where the muscles are not working, which naturally inclines them towards practicing unstable training exercises. However, it is important to note that this only means that the muscles are holding an isometric position. Everyone knows that their core is “working” when they hold a plank on a bosu ball, because they’re resisting the movement of falling on the floor.
You can create stability in a joint whilst it moves as well though. For instance, when doing a heavy bench press the muscles surrounding your shoulder - in particular the lats - are working hard to ensure the joint doesn’t move and change the line of force from the elbow. The more stability you are able to create in your shoulder joint by isometrically holding your lats in position, the more you can contract your pecs into the pushing movement.
We tend to mix up the terms “balance” and “stability” - they are not the same. Stability is a state, balance is a proficiency. Your level of stability is constantly changing based on environmental factors, external influences working on you, and your positioning. Balance is something you have (or lack) to varying degrees; neural factors such as muscular strength, kinesthetic awareness, and coordination play a critical role.
Don’t read this wrong - we are not saying you can’t improve your balance. Nor are we saying that improving your balance has no place in a training program. However, know that when this is the goal, improving your ability to contract tissue and produce force in a joint is compromised.
Ensure your coach uses instability with purpose and a goal, and doesn’t allow it to hamper your progress towards strength improvements.