Mywifesirrational
I however am very normal. Trust me.
I had some time at work, so I thought I might start a thread about core stability as every time some on this forum site asks for training advice, there are always a handful of people citing the importance of training to improve core stability. Then abusing me for my outlandish views and lack of knowledge 
This will be a rambling mess, as I am typing it between testing sessions in a lab.
Disclaimer: I am anti-core stability so this is partially biased, the concept is a complete fail. It has been heavily marketed by stupid PT’s and stupider physiotherapist (who should know better). That being said, a well-rounded exercise program should incorporate some ‘core’ stability, it’s just that the approach that many people take is misguided.
Background (the conclusion will make a lot more sense if you read this):
When we do any exercise that makes our muscles stronger, there are two primarily adaptions, neural and muscular. If you have ever gone to gym for the first time you may have noticed in the first 4-6 weeks you made excellent strength gains, then they slowed down after this period. This occurs because the first 4 weeks we undergo rapid neural adaptations DeVries (1979), with little to no actual muscle morphology adaptation (hypertrophy or bigger muscles).
Specifically:
Normal untrained people cannot fully activate a muscle, so when you maximally load a muscle there’s actually a portion of the muscle that still does not activate - we measure the difference by electrocuting the nerve to the muscle during a maximal voluntary contraction, an increase in force during this is the measurement of your activation level. In the initial 4 weeks to training you ‘learn’ to activate more of the muscle (never all).
During any muscle contraction the opposing muscle (antagonist) will also activate. So during a bicep curl your triceps will activate. This means you have to overcome the force the antagonist creates, meaning your maximal force is reduced by the level of force created by the antagonist. During the first 4 weeks of training, you ‘learn’ to activate the antagonist less, meaning you have more applied force from the agonist.
During a gross movement (compound or a movement that requires lots of muscle to work together), the muscles that help or assist the agonist (prime movers or strongest most important muscle/s in the movement), they learn to coordinate their activation better, this also makes you stronger – imagine a 10 guys pulling a rope all pulling at different times vs all pulling in synchronisation.
There is more to neural adaptations than this, but these are some of the major ones. Now, after 4 weeks, these factors are maximised and muscle morphology changes become dominate. But it MUST be noted that these adaptations are highly specific to the mode of exercise they are learnt in.
Back in 1957 two blokes did a study looking at making muscles stronger by using either isokinetic or isometric training methods (Rasch & Morehouse). Specifically, they did bicep curls standing using a pulley system. During testing after the 4 weeks of training, they compared bicep curls standing (just like every training session) and during supine (laying down face up), remembering the pulley system allows this. What they found was while standing the people had gotten a lot stronger (about 45% from memory), during supine there was no difference in strength. This was the first study to highlight the specificity of neural adaptations have during posture. Conclusion if you want to make a muscle stronger, it must be trained specifically to the posture required. The neural or learning side of strength does NOT transfer to other postures. Application for core stability?
More recently Wilson (1996) found similar outcomes, when training posture after a training program from what was used in the training program. This is a good study with reliable methods, what they found was interesting.
Examples (this is after an 8 week, high intensity training program, so there is also an element of hypertrophy measured here):
Bench Press: 12.4% improvement translated to a 0.7% improvement during a push up.
Squat: 20.9% improvement translated really nicely into a 21.2% improvement in vertical jump (almost identical movement) but only translated into a 2.3% improvement in 40m sprint.
Conclusion, just like what Rasch found, strength improvements are highly specific to the mode and posture they are ‘learn’ in.
Even more recently Goodman and Pearce (my old supervisor ), looked at bench press on a swissball and on a standard bench (He didn’t publish the data). There is no transference of strength from on apparatus to the other, but both made good strength gains on the apparatus (bench or ball) in which the individuals trained on.
So it is clear to me at least and there’s certainly more research out there to support this, the muscle activation underpinning strength gains are highly specific to the mode and method of exercise they are learnt in. So how does rolling around on a floor to develop your ‘core’ help your core stability while you are upright on a bicycle?
Core stability defined and measured:
It is harder to define than most people think – traditionally (mid-late 90’s) it was considered to primarily be the trunk muscles that influenced the lumbo-pelvic region but specifically the muscles between the bottom rib and top of pelvis. The paradigm has shifted to include all muscles that influence the spine, so essentially anything between your neck and knee, i.e. all of your major musculature. This makes more sense to me, as for example a tight hamstring which changes pelvic tilt will also directly affect the lower back (both muscles and vertebrae). This newer definition by default then suggests that focusing on your entire body in an exercise program is a wise thing to do, obviously no surprise there.
How do we measure core stability? Got me stuffed, I don’t think you can. McGill has published a method of measuring core stability improvements, but it is not been scientifically shown to be valid or reliable (but many clinicians will argue it is). So, if we have no proven and effective way of measuring core stability, how can people say it helps their performance – after all you don’t objectively know if you have improved it? (Weir, 2010).
In many studies they have looked at core stability in normal healthy people who are essentially sedentary, core stability works! But they have compared it to the individuals watching television, not any other form of exercise. Conclusion here is core stability training is better at improving your ‘core’ than if you instead simply watched television and did no training.
If you can come up with a valid and reliable measure of ‘core stability’, by all means publish it, you’ll have 1k citations in no time.
In the beginning:
The term core stability was first published somewhere around 94-96, with the first major and heavily cited study by Hodges (a smart bloke from Queensland). They found that when comparing people with good/normal backs to those with bad backs (LBP) there was a timing difference in muscle activation in the trunk. People with good backs activated their ’core’ muscles immediately before (milliseconds) before raising their arm, this is a feed forward mechanism thought to provide stability to the trunk prior to external perturbations. People with LBP, this occurred after they had already raised there arm, meaning no support was provided in the trunk prior to external perturbations. It is a heavily cited study and started the core stability craze; recently there has been some criticism about the methodology. Secondly, there has not been a study ever published to show that if you have LBP and a timing of the muscle discrepancy that this can be changed back to normal.
Prior to the Hodges study, there had been several studies looking at trunk strength and LBP, specifically in pregnancy and after surgery that removed the abdominal wall. There was no relationship shown between no core stability what so ever, most of these people could not even raise their shoulders off the ground, and LBP (Kroll, 1995; Gilleard, 1996; Osgaard, 1991). These studies were completely ignored by the core stability advocates. Although these are clinical issues, not sports training and performance.
Swiss balls:
Probably the most common method the people attempt to develop and improve their core stability, blame the physio’s a PT’s. The premise is that a swiss ball creates an unstable or ‘labile’ surface that requires you to activate your ‘core’ to greater levels over training on a stable surface. The idea being that this will result in improved ‘core’ stability. I know you’re just bursting to know, does the science support this approach even though many of the so called fitness gurus heavily advocate there use?
Lehman (2005) did a variety of exercise on and off a swiss ball and found that there was no difference in core activation between the two methods. The study does not specify the %RM used in the study – this may have made a difference and the conclusion was that training on a swiss ball (doing a variety of dumbbell exercises) does not aid core stability training.
Behm (2002) looked at some leg exercises on a swiss ball vs and bench and a chair. It was found that when on a swiss ball your maximum strength is 20% less than a bench or chair, this means that getting stronger muscle while on a labile surface is not going to happen. They also found that the antagonist was 30% more active, presumably to try and stabilise the pelvis? Conclusion was using a swiss ball MAY be ok if you want to get stronger (note, this was a strength study, not a core stability study).
Lehman (2007) had participants do a variety of push ups in various labile conditions, whilst measuring muscle activity. It was noted that there was very low rates of muscle activation in the agonists, meaning that they would not get stronger or bigger.
There is a lot more research out there to show that training on a swiss ball is not an effective method of improving core stability and it fails completely if you want to get stronger in general. The labile surface causes you nervous system to reduce the activation of the primary muscles in the exercise, which causes them not to improve. The conclusion is if you want to get stronger DO NOT use a swiss ball in you resistance training program.
Core stability and sports performance:
I have had a good dig around in pubmed and medline and I core stability studies looking at studies are extremely rare, which suggests (currently) there is no direct evidence to support the use of core stability in cycling.
Abt (2007) looked at core stability and cycling, their conclusion was that core stability training resulted in “No significant differences were demonstrated for pedaling forces”, it is a little more complicated than that as they also looked into fatigue. I am pretty sure people on this forum advocate core stability for cycling for this very reason?
In a couple of running studies looking at core stability and improvements in performance… Stanton (2004) came to the conclusion “Data from the current study suggest that, while Swiss ball training may positively affect core stability, physical performance as defined by V˙ O2max, vV˙ O2max, or running economy, is not enhanced. Furthermore, muscle fatigue as detected by sEMG appears unaffected by 6 weeks of Swiss ball training”.
Also, Sato (2009) found there was no difference in kinetics or run time after 6 weeks of a core stability training program. Pilates research which has looked at core stability on performance, health, LBP and even weight loss is even worse, no quality research in this area has found anything of interest.
My approach to core stability:
It is really simple, use excellent posture and overload your resistance training, cycle more and do as many forms of cross training as possible, especially things like swimming. I’m not getting paid to give out free advice (my hecs debt is outrageous) so I’ll keep it simple.
Exercise like the squat and the dead lift, these are fantastic ‘core’ exercise. BUT, you must use perfect form. If you can’t use perfect form, the loads too heavy. You don’t decide if your form is perfect, someone else needs to be watching from various angles. There is no such thing as good enough posture for these exercises, if you value you back, it must be perfect. These are complex exercises that load your ‘core’ muscles as well as the agonists.
Seated row or a lat pull down in which you lean back close to 45 degrees. Yet again posture is everything, leaning back puts more stress on the ‘core’ muscles because you are increasing the ‘leverage’ onto them. During any sort of row or latpull down, the trunk should not move at all (with the exception of having full pro/retraction at the shoulder).
An exercise like the plank or side plank is also very good and many people view these entirely as core exercises, but they have been around for decades if in centuries. Great exercises for developing endurance, but terrible if you have hypertension, they’ll put your BP through the roof (because its constant tension unlike repetitions, which allow a pause in muscle contraction).
Throw some shit, you’ll see boxers doing this a lot. Develops upper body strength and power (obviously) but get what muscles have to support the upper limbs during this… rock climb, take up a martial art, oil yourself up and have some man on man wrestle time (don’t let the wife catch you…)
Secondly, don’t waste your time incorporating swiss balls into your strength training program, if you do that you won’t be getting stronger. If you must do some swiss ball exercise, do them completely separate from you resistance training program.
Now what?
I am presuming the people out there that swear by core stability training will continue to engage in it, which is fine by me, it’s your time and I always tell people don’t believe anything you read on the internet. But at least the people who are on the fence or have not been biased by being told (by unqualified people) they must engage in core stability exercises, will use their common sense and ignore this fad and engage in conventional and proven methods of getting stronger, increasing performance and staying healthy.
If anyone wants more advice on their strength and condition practices, and is willing to travel to Deakin Burwood and buy me a coffee… happy to have a chat.
MWI
BAppSci (Human Movement)
MAppSci (Ex Rehab)
PhD (Neurophysiology) current
This will be a rambling mess, as I am typing it between testing sessions in a lab.Disclaimer: I am anti-core stability so this is partially biased, the concept is a complete fail. It has been heavily marketed by stupid PT’s and stupider physiotherapist (who should know better). That being said, a well-rounded exercise program should incorporate some ‘core’ stability, it’s just that the approach that many people take is misguided.
Background (the conclusion will make a lot more sense if you read this):
When we do any exercise that makes our muscles stronger, there are two primarily adaptions, neural and muscular. If you have ever gone to gym for the first time you may have noticed in the first 4-6 weeks you made excellent strength gains, then they slowed down after this period. This occurs because the first 4 weeks we undergo rapid neural adaptations DeVries (1979), with little to no actual muscle morphology adaptation (hypertrophy or bigger muscles).
Specifically:
Normal untrained people cannot fully activate a muscle, so when you maximally load a muscle there’s actually a portion of the muscle that still does not activate - we measure the difference by electrocuting the nerve to the muscle during a maximal voluntary contraction, an increase in force during this is the measurement of your activation level. In the initial 4 weeks to training you ‘learn’ to activate more of the muscle (never all).
During any muscle contraction the opposing muscle (antagonist) will also activate. So during a bicep curl your triceps will activate. This means you have to overcome the force the antagonist creates, meaning your maximal force is reduced by the level of force created by the antagonist. During the first 4 weeks of training, you ‘learn’ to activate the antagonist less, meaning you have more applied force from the agonist.
During a gross movement (compound or a movement that requires lots of muscle to work together), the muscles that help or assist the agonist (prime movers or strongest most important muscle/s in the movement), they learn to coordinate their activation better, this also makes you stronger – imagine a 10 guys pulling a rope all pulling at different times vs all pulling in synchronisation.
There is more to neural adaptations than this, but these are some of the major ones. Now, after 4 weeks, these factors are maximised and muscle morphology changes become dominate. But it MUST be noted that these adaptations are highly specific to the mode of exercise they are learnt in.
Back in 1957 two blokes did a study looking at making muscles stronger by using either isokinetic or isometric training methods (Rasch & Morehouse). Specifically, they did bicep curls standing using a pulley system. During testing after the 4 weeks of training, they compared bicep curls standing (just like every training session) and during supine (laying down face up), remembering the pulley system allows this. What they found was while standing the people had gotten a lot stronger (about 45% from memory), during supine there was no difference in strength. This was the first study to highlight the specificity of neural adaptations have during posture. Conclusion if you want to make a muscle stronger, it must be trained specifically to the posture required. The neural or learning side of strength does NOT transfer to other postures. Application for core stability?
More recently Wilson (1996) found similar outcomes, when training posture after a training program from what was used in the training program. This is a good study with reliable methods, what they found was interesting.
Examples (this is after an 8 week, high intensity training program, so there is also an element of hypertrophy measured here):
Bench Press: 12.4% improvement translated to a 0.7% improvement during a push up.
Squat: 20.9% improvement translated really nicely into a 21.2% improvement in vertical jump (almost identical movement) but only translated into a 2.3% improvement in 40m sprint.
Conclusion, just like what Rasch found, strength improvements are highly specific to the mode and posture they are ‘learn’ in.
Even more recently Goodman and Pearce (my old supervisor ), looked at bench press on a swissball and on a standard bench (He didn’t publish the data). There is no transference of strength from on apparatus to the other, but both made good strength gains on the apparatus (bench or ball) in which the individuals trained on.
So it is clear to me at least and there’s certainly more research out there to support this, the muscle activation underpinning strength gains are highly specific to the mode and method of exercise they are learnt in. So how does rolling around on a floor to develop your ‘core’ help your core stability while you are upright on a bicycle?
Core stability defined and measured:
It is harder to define than most people think – traditionally (mid-late 90’s) it was considered to primarily be the trunk muscles that influenced the lumbo-pelvic region but specifically the muscles between the bottom rib and top of pelvis. The paradigm has shifted to include all muscles that influence the spine, so essentially anything between your neck and knee, i.e. all of your major musculature. This makes more sense to me, as for example a tight hamstring which changes pelvic tilt will also directly affect the lower back (both muscles and vertebrae). This newer definition by default then suggests that focusing on your entire body in an exercise program is a wise thing to do, obviously no surprise there.
How do we measure core stability? Got me stuffed, I don’t think you can. McGill has published a method of measuring core stability improvements, but it is not been scientifically shown to be valid or reliable (but many clinicians will argue it is). So, if we have no proven and effective way of measuring core stability, how can people say it helps their performance – after all you don’t objectively know if you have improved it? (Weir, 2010).
In many studies they have looked at core stability in normal healthy people who are essentially sedentary, core stability works! But they have compared it to the individuals watching television, not any other form of exercise. Conclusion here is core stability training is better at improving your ‘core’ than if you instead simply watched television and did no training.
If you can come up with a valid and reliable measure of ‘core stability’, by all means publish it, you’ll have 1k citations in no time.
In the beginning:
The term core stability was first published somewhere around 94-96, with the first major and heavily cited study by Hodges (a smart bloke from Queensland). They found that when comparing people with good/normal backs to those with bad backs (LBP) there was a timing difference in muscle activation in the trunk. People with good backs activated their ’core’ muscles immediately before (milliseconds) before raising their arm, this is a feed forward mechanism thought to provide stability to the trunk prior to external perturbations. People with LBP, this occurred after they had already raised there arm, meaning no support was provided in the trunk prior to external perturbations. It is a heavily cited study and started the core stability craze; recently there has been some criticism about the methodology. Secondly, there has not been a study ever published to show that if you have LBP and a timing of the muscle discrepancy that this can be changed back to normal.
Prior to the Hodges study, there had been several studies looking at trunk strength and LBP, specifically in pregnancy and after surgery that removed the abdominal wall. There was no relationship shown between no core stability what so ever, most of these people could not even raise their shoulders off the ground, and LBP (Kroll, 1995; Gilleard, 1996; Osgaard, 1991). These studies were completely ignored by the core stability advocates. Although these are clinical issues, not sports training and performance.
Swiss balls:
Probably the most common method the people attempt to develop and improve their core stability, blame the physio’s a PT’s. The premise is that a swiss ball creates an unstable or ‘labile’ surface that requires you to activate your ‘core’ to greater levels over training on a stable surface. The idea being that this will result in improved ‘core’ stability. I know you’re just bursting to know, does the science support this approach even though many of the so called fitness gurus heavily advocate there use?
Lehman (2005) did a variety of exercise on and off a swiss ball and found that there was no difference in core activation between the two methods. The study does not specify the %RM used in the study – this may have made a difference and the conclusion was that training on a swiss ball (doing a variety of dumbbell exercises) does not aid core stability training.
Behm (2002) looked at some leg exercises on a swiss ball vs and bench and a chair. It was found that when on a swiss ball your maximum strength is 20% less than a bench or chair, this means that getting stronger muscle while on a labile surface is not going to happen. They also found that the antagonist was 30% more active, presumably to try and stabilise the pelvis? Conclusion was using a swiss ball MAY be ok if you want to get stronger (note, this was a strength study, not a core stability study).
Lehman (2007) had participants do a variety of push ups in various labile conditions, whilst measuring muscle activity. It was noted that there was very low rates of muscle activation in the agonists, meaning that they would not get stronger or bigger.
There is a lot more research out there to show that training on a swiss ball is not an effective method of improving core stability and it fails completely if you want to get stronger in general. The labile surface causes you nervous system to reduce the activation of the primary muscles in the exercise, which causes them not to improve. The conclusion is if you want to get stronger DO NOT use a swiss ball in you resistance training program.
Core stability and sports performance:
I have had a good dig around in pubmed and medline and I core stability studies looking at studies are extremely rare, which suggests (currently) there is no direct evidence to support the use of core stability in cycling.
Abt (2007) looked at core stability and cycling, their conclusion was that core stability training resulted in “No significant differences were demonstrated for pedaling forces”, it is a little more complicated than that as they also looked into fatigue. I am pretty sure people on this forum advocate core stability for cycling for this very reason?
In a couple of running studies looking at core stability and improvements in performance… Stanton (2004) came to the conclusion “Data from the current study suggest that, while Swiss ball training may positively affect core stability, physical performance as defined by V˙ O2max, vV˙ O2max, or running economy, is not enhanced. Furthermore, muscle fatigue as detected by sEMG appears unaffected by 6 weeks of Swiss ball training”.
Also, Sato (2009) found there was no difference in kinetics or run time after 6 weeks of a core stability training program. Pilates research which has looked at core stability on performance, health, LBP and even weight loss is even worse, no quality research in this area has found anything of interest.
My approach to core stability:
It is really simple, use excellent posture and overload your resistance training, cycle more and do as many forms of cross training as possible, especially things like swimming. I’m not getting paid to give out free advice (my hecs debt is outrageous) so I’ll keep it simple.
Exercise like the squat and the dead lift, these are fantastic ‘core’ exercise. BUT, you must use perfect form. If you can’t use perfect form, the loads too heavy. You don’t decide if your form is perfect, someone else needs to be watching from various angles. There is no such thing as good enough posture for these exercises, if you value you back, it must be perfect. These are complex exercises that load your ‘core’ muscles as well as the agonists.
Seated row or a lat pull down in which you lean back close to 45 degrees. Yet again posture is everything, leaning back puts more stress on the ‘core’ muscles because you are increasing the ‘leverage’ onto them. During any sort of row or latpull down, the trunk should not move at all (with the exception of having full pro/retraction at the shoulder).
An exercise like the plank or side plank is also very good and many people view these entirely as core exercises, but they have been around for decades if in centuries. Great exercises for developing endurance, but terrible if you have hypertension, they’ll put your BP through the roof (because its constant tension unlike repetitions, which allow a pause in muscle contraction).
Throw some shit, you’ll see boxers doing this a lot. Develops upper body strength and power (obviously) but get what muscles have to support the upper limbs during this… rock climb, take up a martial art, oil yourself up and have some man on man wrestle time (don’t let the wife catch you…)
Secondly, don’t waste your time incorporating swiss balls into your strength training program, if you do that you won’t be getting stronger. If you must do some swiss ball exercise, do them completely separate from you resistance training program.
Now what?
I am presuming the people out there that swear by core stability training will continue to engage in it, which is fine by me, it’s your time and I always tell people don’t believe anything you read on the internet. But at least the people who are on the fence or have not been biased by being told (by unqualified people) they must engage in core stability exercises, will use their common sense and ignore this fad and engage in conventional and proven methods of getting stronger, increasing performance and staying healthy.
If anyone wants more advice on their strength and condition practices, and is willing to travel to Deakin Burwood and buy me a coffee… happy to have a chat.
MWI
BAppSci (Human Movement)
MAppSci (Ex Rehab)
PhD (Neurophysiology) current
