There is a saying that Norwegians are born with skis on.
Perhaps that is why the oh so proud winter sport nation left the 2016 Rio Olympics with a measly 4 bronze medals.
The saying does not mention if Norwegians also stubbornly resist the concept of change. But we do.
If something is remotely out of alignment with traditional thinking, we don’t want it. Perhaps if we weren’t so adamantly adhering to tradition we wouldn’t suck at summer sports.
As a result of this stubbornness, thousands of cyclists, triathletes and runners bore themselves to sleep through weekly routines of core exercises.
Miserably unaware that they might have achievet greater results with different and much more exciting modes of training.
It’s time to have a closer look at the science of core stability and athletic performance.
This text was originally written for Norwegian cyclists. However, the topic is pertinant to other endurance athletes, coaches and clinicians alike. After numerous requests from colleagues I finally completed an English translation. The post is quite extensive. If you want to quickly get the gist of it I suggest you: - skim through the subheadings - read the summary at the bottom - save this post in your web browser Use the below links for quick navigation within the post. 1. Introduction 2. Core stability and performance 3. Core stability and injuries 4. Strength and performance 5. Strength and injuries 6. Summary
I spent my entire athletic “career” doing core stability exercises. I have prescribed them to patients. I have recommended them for friends and family.
If there is one topic where my credentials “Chiropractor & Medical Student” carries some weight, I would think the role of spinal stability would be it.
Funny how your years of university training are often proportional with the amount of overconfidence by which you present your beliefs. Questioning those beliefs requires a different confidence entirely.
It would take me years to get to that point regarding core stability training.
In that regard, this post is a reflection upon my years of being wrong. On what I have practiced with best intentions at heart, but sadly, with flawed or just plain incorrect explanations.
My reason for engaging in this discussion is as follows:
“I want you, the cyclist, the up and coming athlete, the fitness-loving student at the campus gym and the seasoned recreational runner to get the best bang for your buck with the time you invest in your training.”
My question to you is this: what training modalities gives you the best possible outcome per hour of training?
Core stability training might have less to do with the answer than you think.
The term core stability training is often used with different meanings. Some authors confine its use to exercises targeting abdominal and lower back muscles. Others use the term less strictly, including any work addressing stability between the chest and knees.
Reed et al have proposed the following definition (1):
“…core stability can be thought of as maintaining control of the core during the application of core strength or in response to a perturbation.”
For this post I will reserve the term core stability for exercises directed towards abdominal, spinal and hip muscles.
Such training is often advocated to improve balance, muscular recruitment or muscular endurance. With the end goal being improving stability of the axial skeleton, and thereby facilitating enhanced performance.
Picture your dead bugs, bridges, bird dogs, back extensions, sit ups, side bridges, glute raises and the likes of exercises commonly performed on the floor, ball, in ropes or on other unstable surfaces. Typically, the work performed is charactarised by low resistance, many repetitions or sustained isometric contractions.
Strength is a different entity
Take note that core stability is not to be confused with strength. Raastad et al defines strength as:
“…all training performed with the intention to develop or maintain the ability to create maximal force at a specific or predetermined speed.”
Strength training is typically performed with greater resistance so that fatigue is achieved within 1-12 repetitions. This is involves greater force production than that involved in the core stability training we are addressing.
What is the purpose of a stabile core?
In theory, core stability training makes perfect sense. Newton’s third law states:
“When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.”
– Sir Isaac Newton
This means the greater force you exert downwards into your pedals, the greater the resulting force acting back upon your body becomes. In order to achieve maximum energy transferral to the pedals, you must avoid the resulting force from creating unnecessary movements of your body.
You need to stabilise your torso.
The common notion is that great core stability allows greater maximal force development and more efficient use of muscles in shoulders, arms and legs (2). In theory this should result in decreased injury risk and increased performance through enhanced speed, mobility, power and endurance (3).
It is hard to argue with this rhetoric. Which is probably why so many athletes put themselves through endless repetitions of planks, sit-ups, back raises and other stability exercises every week.
The pertinent question is: does this training work as well as we believe it to?
Highly uncertain if core stability training improves athletic performance
A lot of trainers and therapists talk an impressiv game when promoting core stability exercises. Not until you examine the science on the matter do you realise the logic is littered with cracks and holes.
Angela E. Hibbs is a PhD candidate in the field of core stability training and its role in improving stability, strength and athletic performance. In Sports Medicine in 2008 she states (4):
“Many elite athletes undertake core stability and core strength training as part of their training programme, despite contradictory findings and conclusions as to their efficacy.”
This goes a long way in suggesting that our knowledge on core stability training is not as good as we believe it to.
A sound theoretical rationale for any training method is of litte value if you cannot also demonstrate that the training yields the real life results you expect it to.
Upon closer inspection of the current literature on core training you will find that Hibbs’ suggestion is on the money.
When it comes to cycling there is hardly any good research available. The only study I have been able to dig up on core stability and cycling performance was the following.
Relationship between cycling mechanics and core stability An article in Journal of Strength and Conditioning Research looked into a possible influence of core stability on pedaling biomechanics (5). 15 competitive cyclists performed an exhaustive cycling test while measuring power and biomechanics. The cyclist later undertook a 32 minute workout with 7 exercises designed to exhaust core muscles in multiple planes. The cycling test was then repeated immediately following. To the authors' surprise there was no reduction in pedaling power with core muscle fatigue: "The lack of changes in pedaling forces, specifically during the recovery phase, was somewhat surprising considering our hypothesis that disrupting core stability would result in a reduction in pedaling effectiveness during the recovery phase." ** Abt JP et al. Journal of Strength and Conditioning Research, 2007
** It is worth noting that the cycling test was performed at fixed speed and gears. The authors argue that this might have “forced” the rider into a certain power output and eliminated any changes that might have occured with a free choice of speed and gears.
Nevertheless, the fact remains that no studies performed on cyclists can demonstrate that improved core stability results in better cycling performance.
Like cyclists, swimmers too must overcome the resistance of their surrounding element. And because the athlete is free floating in water, the torso becomes the single reference point for movement (6). This fact is used as an argument in the recommendation of Swiss ball exercises for swimmers (7-8).
Yet again, recommendations are made without backing from hard data.
The effect of core stabilization training on functional performance in swimming In a masters thesis from 2001, Schibek et al investigated the effect of Swissball exercises on athletic performance in swimmers (9). The athletes were assigned to an experimental group and a control group. Only the experimental group performed core stability exercises. After the intervention period the experimental group achieved better results in two out of five land based exercises. However, when testing performance on 100 swimming, no difference between the two groups were seen. Master's thesis, University of North Carolina, 2001
Similar work has been done in other sports. A study on rowing in 2005 reached a similar conclusion. Core stability exercises improves core stability, but fails to enhance rowing performance (3).
“In summary, the 8-week core endurance training program improved selected core endurance parameters in healthy young men, but the effectiveness of the core intervention on various functional performance aspects was not supported.”
The aforementioned Swissball exercises are widely used due to their alleged relevance to sports-specific movements. Yet, few studies have investigated the effect of said exercises on actual athletic performance (6).
The effect of short-term Swiss ball training on core stability and running economy Stanton et al investigated the effect of Swissball exercises on core stability, VO2 max and running economy in runners (10). Athletes were assigned to either an experimental group or control group. Both groups performed regular running traing. In addition, the experimental group undertook Swissball exercises. After the intervention period the experimental group performed significantly better when testing core stability. However, there was no significant difference between the groups for either VO2 max or running economy. Stanton and colleagues conclude: "While a wealth of anecdotal evidence supports the use of Swiss ball training to enhance physical performance, this has not been substantiated by valid scientific investigation." Stanton et al, Journal of Strength and Conditioning Research 2004
Collectively, the above studies demonstrate an important point. Enhanced core stability does not necessarily improve athletic performance (6).
“There is no guararantee that improvements in core strength and power will transfer to improvements in sports performance.”
Are there no studies that can demonstrate improvement in athletic performance following core stability exercises?
In 2012 Reed and colleagues systematically reviewed the existing literature on this field. Among the studies included in their review I can see only one that pertains to enhanced endurance performance (1).
This study is described in further detail below.
Does core strength training influence running kinetics, lower-extremity stability, and 5000-m performance in runners? In 2009 Sato and Mokha tested the effect of core exercises on 5000 meter running performance in 18 amateur runners (11). The subjects were assigned to either an experimental group or a control group. They then completet a 5000 meter running test prior to undertaking a 6 week training program. The control group did their usual running training. The experimental group also added the following 5 core exercises to their training. - Sit-up on ball - Back extension on ball - Crossed arm and leg raise - Glute raise on ball - Russian twist on ball This series of exercises was performed four times weekly with the following numbers of sets and repetitions: Week 1-2: 2 x 10 reps Week 3-4: 2 x 15 reps Week 5-6: 3 x 12 reps Following the six week training period a second 5000 meter running test was performed. As it turned out, the experimental group (with core exercises) achieved a greater improvement in running time than the control group [47 seconds vs 17 seconds improvement]. Sato og Mokha, Journal of Strength and Conditioning Research, 2009
Several aspects of this study is worth discussing.
The experimental group performed core stability exercises four times weekly. This is more frequent than what have been used in other experiments. Perhaps this is why this study succeeded in demonstrating a significant difference following core training?
Looking closer at the data you will also see that the control group had a dramatically better performance before taking on core stability training [26:30 vs 29:29 in 5000 m]
You could argue that the higher the initial level of athletic performance, the more difficult further improvement will be to come by. This difference in initial performance level might have contributed to the core training group achieving greater improvement. If so, the actual effect of the core stability training would be less than initially indicated by this study.
Here comes an eye opener. The few studies referenced above constitute all the research there is on the effect of core stability training on performance in athletes.
Consider how widely recognised the use of core stability exercises is. Yet, all we got to show for is a handful of studies. Of which the majority reports no added effect of stability training.
It turns out Angela Hibbs’ statement from 2008 still applies:
“There are many articles in the literature that promote core training programs and exercises for performance enhancement without providing a strong scientific rationale of their effectiveness, especially in the sporting sector.”
So far we have only been looking at direct measures of athletic performance.
However, athletic performance at a high level requires continuous training over time. As such, breaks in training due to injury is detrimental to performance.
Could it be that core stability training carries a long term effect on injury prevention? An effect that the current literature have failed to reveal?
Hibbs makes that exact suggestion (4):
“It might be that improvements made in stability and strength only impact indirectly on sporting performance by allowing athletes to train injury free more often.”
Core stability exercises are commonly recommended as a injury preventative measure (6). Therapists, coaches and scientists alike support the protective role of core stability for athletes (3, 12-14).
Is there any evidence to suggest such an effect?
A common thought is that insufficient core stability leads to poor technique, which in turn increases the risk of injuries.
This argument is also presented in the study on core stability and cycling biomechanics. Following a core muscle fatigue protocol increased knee movements were observed during pedaling (5).
The authors suggest this might increase the risk of overuse injuries.
“Core fatigue resulted in altered cycling mechanics that might increase the risk of injury because the knee joint is potentially exposed to greater stress.”
Studies have shown that athletes [basketball & track and field] who endure back or lower extremity injuries in general have inferior core stability compared to healthy athletes (16). However, in these studies, core stability encompassed hip muscle activity only.
I have been able to identify one study that demonstrates decreased injury rates following core stability exercises.
Effect of stabilisation training on trunk muscle size, motor control, low back pain and player availability among elite Australian rules football players This study from 2011 investigated the possible preventative effect of core stability exercises on back pain and training availability in Australian rugby players. Following core training a decrease in back pain and increase in player availability for training was observed. Hides J et al. British Journal of Sports Medicine, 2011
Similar results were found in a study on gymnasts in 2009. The authors reported fewer cases of back pain following a 10 week period of core stability training (7).
Unfortunately, this study did not include a control group for comparison [a similar group of athletes not doing core training]. Therefore, we cannot know if the decreased back pain is due to the core training itself or other variables.
It is worth noting that balance training appears to have a well documented effect on anterior cruciate ligament injuries (6). However, this might very well be due to effects on local knee structures, rather than improved than improved pelvic and spinal stability.
Again, there seems to be an established “truth” that core stability is essential in preventing injuries.
Again, the conclusion is based largely on assumptions rather than solid evidence.
No superior therapy for existing pain and injuries
How about treatment for pre-existing injuries and painful conditions? Like common back pain? Surely, core stability must play a central role here?
Three recent publications have reviewed the research on core stability training for back pain (18-20). Let us have a look at their conclusions.
“There is strong evidence stabilisation exercises are not more effective than any other form of active exercise in the long term. … further research is unlikely to considerably alter this conclusion.”
“Our results found a beneficial effect for strength/resistance and coordination/stabilisation exercise programs over other interventions in the treatment of chronic low back pain and that cardiorespiratory and combined exercise programs are ineffective.”
“Little or no difference is observed between motor control exercise and other forms of exercise. Given the minimal evidence that motor control exercise is superior to other forms of exercise, the choice of exercise for chronic low back pain should probably depend on patient or therapist preferences, therapist training, costs and safety.”
Two out of three reviews conclude that stability training is no more effective than general exercise. The third suggests coordination and stability training is as effective [but, no more effective] than traditional strength training.
This might come as a surprise to many athletes. It just makes good sense that core exercises should be a superior cure for back pain.
That is when you need to remember that pain, sports injuries included, is a complex phenomenon. Quite often, pain intensity will be grossly out of proportion with the degree of structural injury.
This is particularly true for back pain. For the majority of athletes presenting with lower back pain, no tissue damage can be identified. Also, the notion that back pain can be explained by poor core muscle function alone has been thoroughly debunked (21).
Unfortunately, this myth is alive and well amongst athletes, coaches and therapists alike.
There is little evidence to suggest that core stability training is a superior solution for those suffering from back pain, or other sports-related injuries.
Rather, the important message with back pain seems to be that general movement is beneficial – regardless of how you are training.
Core muscles do not work in isolation
There are many myths surrounding core muscles and their alleged role in health, pain and athletic performance.
In a recent article Wirth et al thoroughly dissects the core stability literature (22). This article should be compulsory reading for all trainers and therapists.
For those of you not accustomed to reading academic publications I will summarise some of the take home points below:
The often-used classification of muscle into “local” and “global” systems, as the way to discriminate between muscles responsible for inter-segmental stability and spine motion, is incorrect.
In the late 1990s, certain core muscles caught the eye of a group of researchers (23-26). In particular, the function of m. obliquus transversus and m. multifidus became a center of attention.
Meanwhile, the notion that spinal muscles could be divided into “local” and “global” by their respective functions was catching hold in manual therapy circles (4, 27-28).
The idea was that these two systems each were responsible for particular and separat tasks in creating spinal stability during movement. The “local” muscles were thought to stabilise the spine, while the superficial “global” muscles created the necessary force to create movement.
At least, so we thought.
Thanks to eager interpretation of current research a global industry of exercise programs to isolate the “local” spinal stability system arose.
Today we know that the muscles of the spine and abdomen do not work in such simplistic isolation. On the contrary, the different muscular layers cooperate to achieve stability. And they distribute the work varyingly depending on the movement to be carried out (29-32).
For a further clarification on this topic, see this interview with Professor Paul Hodges.
Wirth also draws the attention to the practice of recommending exercises on unstable surfaces over traditional strength training. This training is assumed to closely resemble sport-specific movements and daily activities.
Another argument presented in favor of exercises on unstable surfaces has been that deeper core muscles of “local” muscle systems were particularly strengthened. Again, no proof is available.
He further makes the point that such a claim is unreasonable, since the majority of sports and every day activities are performed on a stabile and non-moving surface. Wirth suggests that exercises on unstable surfaces should be deemed non-specific, seeing how they do not recreate the loading achieved in sporting events.
Today, we know that the interplay between the muscular layers contributing to core stability is (21,29,33):
- highly variable
- very dependent on the movement to be performed
This underpins the suggestion that core training should closely mimic sport specific movement.
Strength training in prevention, rehabilitation, and strength and conditioning … should be as similar as possible to everyday and sport-specific movements.
Wirth and colleagues highlights that many athlete programs recommend exercises such as kneeling hip raise, bridges and sidebridges:
It seems surprising to find such exercises … since we cannot think of any situation, either in sports or in daily life, where those motor actions take place. Therefore, we conclude that these training exercises are neither “specific” nor “functional” and thus should not be recommended.
You may agree or disagree to the above arguments.
However, you cannot refute the point that a lot of the commonly accepted “truths” concerning core stability exercises are based on lacking evidence or wrongful assumptions.
There is good reason to wonder if a lot of the recommended core training regimes are unnecessarily complicated.
Why you should not write off core stability training completely
So far I have been fairly critical towards core stability traing. More presicely, I have highlighted the lacking evidence to support the use of this common method of training.
Still, there are several arguments as to why core stability training might still play a role in athletic performance;
1 | A lack of evidence is not evidence of a lacking effect
Several questions regarding core training lack scientific grounding for conclusions to be made. Other questions have some research that shows a tendency towards negative results.
That still does not exclude the possibility of future studies demonstrating positive effects with core stability training.
2 | Are the current exercise interventions well enough designed?
We cannot exclude the possibility that current research use insufficient exercise regimes when it comes to demonstrating an effect of core stability training.
For instance, we have seen that the one study that reported improvement in running capacity included four weekly sessions of core training (11).
It could be that other studies did not implement training often enough, hard enough or long enough to achieve the desired effect.
3 | Could it be that core training yields results that are difficult to measure with current study designs?
Some phenomenon are notoriously difficult to map out with experimental research. Such examples are long term effects of different diets and how to best organise a long term training program.
You could hypothesise that core stability training in time results in a slight reduction of injury risk. One that over months and years allows the athlete more training days and fewer injury breaks.
Continuity in training is a well established necessity for athletic success. A reduction in days out with injury could therefor lead to long term improvements in athletic performance.
All three arguments above are plausible reasons not to write off core stability training completely.
All the while, let’s review the reason for having this discussion – which form of exercise yields the greatest improvement in athletic performance?
In light of the lacking evidence base surrounding core stability training we should add a second question:
Are there methods that with greater certainty will provide you with similar, or better results than core stability training?
It appears to me the answer is “yes”.
Should you spend more time on your bike instead?
An obvious alternative worth exploring is replacing stability training with more time on the road.
Most cyclist have a passions for riding their bike, and would prefer doing so over performing core exercises every day of the week.
Does two weekly sessions of core stability exercises really make you a better cyclists than you would become by spending an extra hour on your bike?
I don’t hold the answer to that question. Nor have I been able to find literature that makes the comparison. It certainly is an interesting question.
For now, all we can do is speculate as to which option is the most effective.
However, if you are to choose between two means with unknown effect, why not go for the fun option?
Endurance athletes tend to steer away from traditional strength training in their pursuit for glory. When reviewing the evidence, you begin to wonder why that is.
Strength training has proven to result in a range of beneficial physiological adaptations for cyclists. The results are in fact so impressive that if you are a cyclist looking to improve your performance, strength training would be one of the top training tools to consider implementing.
One might wonder if the low utilisation of this well-documentet training method is due to trainers and athletes not having enough knowledge on the field (35).
Traditionally, for unknown reasons, endurance athletes have been cautious to strength train. … This philosophy may be due to endurance athletes and coaches being uneducated in strength training science and the associated potential performance improvements.
Let us increase this level of knowledge.
The term strength training is used synonymously with resistance training. This involves performing training with enough resistance to achieve fatigue within 1-12 repetitions (36).
A recent Norwegian study investigated the effect of strength training on cycling performance in elite level cyclists (37). Let us have a closer look at what they found.
10 weeks of heavy strength training improves performance-related measurements in elite cyclists 20 elite cyclists competing at national and international level were divided in two groups. For 10 weeks the experimental group performed strength and endurance training. The control group performed endurance training only. Strength training consisted of 2 weekly sessions of 4 exercises: - Squat - Leg press - Standing one-legged hip flexion - Ankle plantar flexion 3 sets of each exercise were performed with the following number of repetitions for weekly session 1 and 2: Week 1-3: 10RM and 6RM Week 4-6: 8RM and 5RM Week 7-10: 6RM and 4RM *RM is short for "repetitions maximum". 10RM means enough resistance to achieve fatigue by 10 repetitions. Following the intervention period the group with strength training achieved better maximum power and a tendency towards better threshold power. The strength group also displayed greater improvements in a 40 minute all out test, although this difference did not achieve statistical significance. Rønnestad et al. Journal of Sports Sciences, 2016
Elite athletes already perform at a level that makes further performance improvement difficult to achieve. When studies, such as this, demonstrate a superior result compared to traditional training this goes a long way in suggesting the potential effect of the method.
It would be natural to assume that strength training would also benefit performance of riders below elite levels. This has indeed been demonstrated.
25 weeks of concurrent endurance and strength training resulted in larger improvements in cycling performance and performance-related factors, including earlier peak torque during the pedal stroke in elite cyclists. … The present findings are in agreement with previous findings in moderate to well-trained cyclists.
In the above study they found that maximum power, threshold power and mean power over 40 minute all out testing experienced a greater improvement in the group that included strength training in their exercise routines (38). The difference in improvement between the experimental group [Endurance & Strength = ES] and the endurance group [Endurance = E] was significant:
- Maximum power: ES +3% vs E -3%
- Threshold power: ES +3.2% vs E -4.1%
- Mean power in 40 min all out: ES +6.5% vs E +0%
A similar study by Vikmoen et al on female riders provided comparable results.
Adding heavy strength training improved cycling performance, increased fractional utilization of VO2 max, and improved cycling economy.
Again, the results were in favor of strength training [ES] for performance indicators such as threshold power [ES +7.6% vs E +4.1%] and mean power in the 40 min all out test [ES +6.4% vs E +2%].
Vikmoen and colleagues also demonstrated how strength training improves endurance performance by improving fractional utilisation of VO2 max (39).
They also produced data indicating that the effect of strength training on endurance performance might be due to a combination of muscle hypertrophy and conversion of fast twitch muscle fibers to more fatigue resistant fiber types.
The decisive moments of bike races often occur after hours of riding. This means lab data collected from riders in a rested state might not necessarily translate directly to real life performance.
Hansen and colleagues adressed this problem by giving their riders a 5 minute all out test following 3 hours of riding (40). Again, the cyclists who had performed strength training came out on top.
Adding heavy strength training to usual endurance training in well-trained cyclists improves pedaling efficacy during 5-min all-out cycling performed after 185 min of cycling.
The strength group improved their 5 minute mean power from 372 to 399 watts. The endurance group achieved mean power values of 385 and 380 watts.
Summarised, the strength group increased their mean power by 27 watts over the course of the training intervention period. The endurance group suffered a decline by -5 watts.
A common notion among cyclists is that strength training only improves the ability to produce high power values over short time periods. As you have now seen, there is sufficient evidence to effectively debunk this assumption.
The literature presented above demonstrates how resistance training enhances well-known parameters of endurance performance such as threshold power, utilisation of VO2 max and mean power in 40 minute all out tests.
Strength training improves watt per kilo
In cycling, the power to weight ratio is crucial to the ability to perform at a high level. One can easily imagine how this could keep a rider from applying weight training, in fear of increasing his or her body mass.
There is no evidence to support this concern.
Adding strength training to usual endurance training improved determinants of cycling performance as well as performance in well-trained cyclists. Of particular note is that the added strength training increased thigh muscle cross sectional area without causing an increase in body mass.
The above study demonstrated that strength training does give increased thigh cross sectional area. However, this increase was found without the rider putting on weight (41).
It is thoroughly established that strength training provides the benefits of increased muscle cross sectional area, such as:
- increased total mitochondria count, improved utilisation of VO2 max
- which allows for improved threshold power
- more muscle fibers in parallel, which increases maximum power
All this without riders gaining weight.
3 more benefits of strength training
When it comes to documenting the effect of resistance training on cyclists, producing supportive evidence is like pulling rabits out of a hat.
Maximal strength training for 8 weeks improved cycling economy and efficiency and increased time to exhaustion at maximal aerobic power among competitive road cyclists … Based on the results from the present study, we advise cyclists to include maximal strength training in their training programs (42).
We showed that the studied combination of weight training and endurance training increased maximal power output in the full range of cadences between 40 and 120 rpm. Furthermore, both combined resistance-endurance training groups improved the mean power output in the 30-min endurance performance test … (43)
The addition of explosive and high-resistance interval training to the programs of already well-trained cyclists produces major gains in sprint and endurance performance, partly through improvements in exercise efficiency and anaerobic threshold (44).
Results were a 6.1% reduction in the time to comple the 20 km time trial, a greater cycling economy, and power output in the first 10% of the time trial … These results suggest that 5RM strength exercise bouts improve the performance in a subsequent 20 km time trial (45).
Her first bike rice victory ever: a real life example of resistance training Spring 2016 I received the following message from a reader who had set an ambitious goal for herself. Having never won a bike race she set out to win the bike race "Sognefjellsrittet", a 137 km race crossing the highest mountain pass in Northern Europe. One of the measures she took was implementing strength training in her work out schedule. "Hi! Quick feedback. So far the project is gold! I am now able to easily drop the riders I was racing with all last season. They have done business as usual - my only change is adding resistance training. I can hardly believe the difference, it is that big of a change." Some time later that spring her facebook profile read: "I rarely gloat in pride, but today I do. What a day :) 2nd in Randsfjorden Rundt and 7/99 over all. Definitely on schedule for the big goal this season." Later, she accomplished her goal by taking home the victory in Sognefjellrittet. The success of a single rider can never constitute proof of effect. However, it does demonstrate that strength training can easily be implemented in the work out regimes of ambitious amateur cyclists.
Would you like better cycling economy, sharper finishing skills and improved time trial riding? Then you can safely consider applying strength training to your season plan.
Let me repeat, yet again, the central topic of the day:
Are there other training methods that, with greater certainty provides a similar or better performance enhancement than core stability training?
The evidence strongly suggests there are.
I have encountered several athletes that don’t want to take up resistance training in fear of sustaining injury.
Surely there must be a significan risk of overuse injuries when performing heavy strength training?
Human beings sustain pain and injuries in all kinds of trivial activities of daily living. Although you might have heard of people getting pain during weight training, there is little evidence to suggest resistance training is much of a risk.
This question of safety is often raised in coaching young athletes. In a joint statement from the National Strength and Conditioning Association you can read the following (46):
Youth resistance training: updated position statement paper from the national strength and conditioning association "A properly designed and supervised resistance training program: 1. is relatively safe for youth 2. can enhance the muscular strength and power of youth 3. can improve the cardiovascular risk profile of youth 4. can improve motor skill performance and may contribute to enhanced sports performance of youth 5. can increase a young athlete's resistance to sports-related injuries 6. can help improve the psychosocial well-being of youth 7. can help promote and develop exercise habits during childhood and adolescence" Regarding the potential injury risk they continue: "In the vast majority of published reports, no overt clinical injuries have been reported during resistance training." Faigenbaum et al, Journal of Strength and Conditioning Research, 2009
In other words, there is little to suggest young athletes cannot safely take on a well planned and age-adjusted strength training program.
That being said, we are not all in our youth. So how about the more senior athletes? Is the potential injury risk any different to them?
In a literature review on strength training for people over 60 professor and medical doctor Frank Mayer and colleagues state (47):
Diverse studies that we have already cited have shown … that the rate of side effects is very low if the dose is adapted to the patient.
In my research for this article I have been unable to find a single source that can demonstrate that strength training adds any more of an injury risk than that which is associated with all kinds of exercise.
On the contrary, it would appear increasing your muscle strength is one of the most effective measures you can take to prevent sport-related injuries (48).
The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials This meta-analysis included data from 26 610 athletes and 3464 sport-related injuries. The authors considered the evidence for injury-preventative effects of stretching, proprioceptive training and strength training. They reached the conclusion that both proprioceptive training and strength training contributes to injury prevention. Of the two, the larger effect is seen with strength training. It is suggested that the above training can prevent 2 out of 3 sport-related injuries and every second overuse injury. Lauersen et al. British Journal of Sports Medicine, 2014
If you are a cyclist this should be interesting reading considering the high rate of overuse injuries among riders.
In a recent investigation on Norwegian cyclists one out of two riders reported having suffered from injuries during the last 13 weeks (49). This pertained to overuse injuries only, not including crashes and trauma.
From what I can see, the most present risk associated with strength training is the same as will all other types of exercise.
Training too hard, too fast, too soon is the easiest way of getting yourself sidelined with injuries.
As long as you plan your training according to your current shape and background, and apply a reasonable progression, the evidence suggest that strength training gives you “2 for the price of 1” in enhancing performance and preventing injuries.
Strength training might also improve core stability
Could classic strength training in itself provide the necessary core stability for athletic performance? A long line of professionals seem to think so.
Core stability is a product of muscle mass [contractile potential] and neurological activity [stimulating utilisation of this potential] (22).
Wirth and colleagues argue that traditional resistance training affects both muscle mass and neural input to muscles. As opposed to lower resistance core training that only addresses the latter of the two components.
Regarding the lack of core muscle activation that some athletes and patients allegedly suffer, Wirth and colleagues propose (22):
… it is possible that missing stimuli in everyday life lead to very low levels of activation … Strength training can counteract this problem.
Do we need isolated workouts to achieve neuromuscular facilitation if strength training can achieve this and enhance muscle mass at the same time? A pertinent question indeed.
Some authors and athletes are apprehensive about applying such a strategy. Their fear is often rooted in a belief that excessive strength training of “global” muscles will cause muscular imbalances.
However, recall that we have already established that muscles DO NOT work in separate “local” and “global” systems.
Still people claim that such training will result in superficial muscles dominating the task of spinal stabilisation, which would in turn lead to restrained and compensatory movement patterns (22).
Again, Wirth and colleagues makes a important argument:
However, there is no scientific evidence to support this statement. … there is no evidence that classical strength-training exercises, for example, squat, deadlift, snatch, and clean and jerk, affect “global” muscles only or lead to imbalances between the muscles of the trunk.
Therefore, we recommend the use of classical strength-training exercises as these provide the necessary stimuli to induce the desired adaptations.
A similar line of thought is presented by other authors (6).
The bottom line is that healthy athletes who already perform traditional resistance exercises, such as the deadlift, squat, power clean, push-press, and Russian-style rotation, are likely receiving sufficient core stability training …
Traditional resistance exercises, such as the deadlift, squat, power clean, push-press, and Russian-style rotation, can be modified further to place greater emphasis on core stability.
Based on the current literature, free weight exercises performed while standing on a stable surface should be the primary training modality to develop core stability and enhance sports performance in healthy athletes.
What is more, the question of whether strength training yields better core stability is beside the point.
Strength training is already well documented to improve the end goal the we wanted to address – real life athletic performance. Whether or not the mechanisms of this performance enhancement includes improved core stability is a question of academic interest mostly.
Authorities recommend strength training for athletes and cyclists
I am certainly not alone in having these opinions on the role of strength training in performance enhancement for cyclists.
Over the last couple of years, numerous scientists and authorities on cycling training have recommended resistance training – for cyclists and other endurance athletes alike (50-53).
… sport scientists and practitioners could conclude that there may be no substitute for greater muscular strength as it underpins a vast number of attributes that are related to improving an individual’s performance across a wide range of both general and sport specific skills while simultaneously reducing their risk of injury when performing these skills.
The present research available supports the addition of strength training in an endurance athlete’s programme for improved economy, velocity/power during during maximal oxygen uptake, muscle power and performance.
Combining endurance training with either explosive or heavy strength training can improve running performance, while there is most compelling evidence of an additive effect on cycling performance when heavy strength training is used.
The authors recommend replacing a portion of an athlete’s endurance training volume with explosive resistance training to increase time trial performance and maximal power output and to minimize the risk of fatigue from an overwhelming total training volume.
The cycling enthusiast can take pride in knowing that a solid chunk of the evidence supporting these statements comes from research performed on cyclists.
How to perform your resistance training
My favorite quote concerning training is:
Keep it simple, stupid.
In line with this thought – how are you supposed to synthesise all of the information above for application to your every day training?
Based on the available literature, I would suggest that strength training for the healthy cyclist should adhere to the following:
- use exercises that closely resemble the movement patterns of your sport
- use sufficient resistance to induce muscle hypertrophy
- use high speed movement during concentric work
The above is in line with the recommendations of Rønnestad. It also reflects the training methods that are scientifically proven to improve cycling performance (37-39,41,52).
As previously mentioned, several studies have included the following exercises:
- Leg press
- Standing one-legged hip flexion
- Ankle plantar flexion
Exercises are usually performed in 3 sets of 4-10 repetitions. The eccentric phase is performed with slow movements [2-3 seconds]. The concentric phase is done in a rapid movement [1 second].
For a squat this means you sit down slowly and get back up quickly.
One obvious and safe solution would be to copy-paste this program in its entirety.
Strength training at home
What if you don’t have access or opportunity to get to a gym with the necessary weight lifting equipment?
Tt is quite possible to get some of this power development with some creativity and using your body and free weights as resistance.
Squatting with a barbell can be replaced with a pistol squat [as demonstrated below]. If you are already a beast, add a light dumbbell.
You can also perform a free standing squat with a kettlebell in one arm. Adding resistance to one side of the body only increases the stimulus to engage core stability.
The standing one-legged hip flexion is easily done with an elastic rubber band [a solid one].
Depending on your current strength, creating sufficient resistance for the ankle plantar flexion exercise can provide a challenge. However, try standing on one leg, fill your larges backpack with old frying pans and phone books and you will likely feel the burn during your third set of 8RMs.
The take-home-point is to follow the principles of specificity pertaining the relevant movements of your sport and ensuring sufficient resistance.
Not all athletes should abandon core training
Are there cases where I would still recommend the use of core stability training?
Yes, I can think of numerous.
However, before going into detail about these, allow me to repeat the take home message:
The effect of core stability training on cycling performance is, most likely, marginal (1). In comparison, strength training provides a well documented performance enhancing and injury preventative effect.
That being said, there are some athletes that could probably benefit from core stability training.
The young athlete
In the Norwegian publication Treningsanbefalinger for å bedre sentrale fysiologiske faktorer i sykkelprestasjon several well-published sports scientists and world class cycling coaches review the current evidence and best practice in cycling training.
They recommend that young cyclists hold off heavy resistance training until the age of 18 (54). This recommendation is based, not on a fear of injuries, but on a belief that young athletes should focus on developing aerobic endurance up until this point.
The authors suggest general core stability training should be systematically implemented in training from the age of 10.
For this use the classic core stability training that you are familiar with serves it purpose. Low resistance exercises for back, abdominal and hip muscles can be combined with exercises with greater resistance and bouts of plyometrics, balance and agility training (55).
Integrative neuromuscular training initiated in pre-adolescence and maintained into adolescence will maximize training age and the potential to achieve optimal adulthood motor capacity.
The elite cyclist
You have probably watched the Tour de France and heard stories of how a certain rider became a much better time trialist after taking on core stability training.
These riders are in a fundamentally different position than the other 99.9% of the world’s cyclists.
For most of the year they got the entire day dedicated to training and resting. They are pushing the boundaries for the amount of endurance training the body can endure. They compete at a level where every single percentage of performance can be the difference between victory and defeat.
Yes, the effect of core stability training is most likely marginal. But for these riders, that margin might be the deciding factor.
If you are a highly ambitious amateur rider with a great training volume, this could of course go for you too.
However, for the average amateur the question remains if there are bigger gains to be made with other and more time effective means.
The injured athlete
Low resistance core training does have its place in treatment of pain and injuries.
For instance, it is fairly well documented that core exercises has a positive effect on sub-acute and persistent back pain.
The caveat is you must know that this is one of many ways of dealing with such problems.
The point being that when multiple interventions seems to work, therapy should be designed to fit the athlete/patient’s needs and preferences. Some athletes would probably prefer core stability training as an early step in their recovery.
The underperforming cyclist
Sometimes you do everything by the book. But still you don’t perform as well as expected.
Such a situation could have a 1001 possible causes. One of these might possibly benefit from core endurance training.
Me: As a clinician, I have come across athletes in cycling, and other sports, that appear to be doing everything correctly. They do sufficient amounts of endurance training and have already implemented strength training in their programs. Yet, they still feel they lack the "punch" they should be having. Typically, they have a history of back or hip pain/injury. With some of these cases I have witnessed surprisingly rapid return to normal performance levels following a brief period of endurance training of back and hip muscles. In these cases we are talking exercises addressing spinal muscles in extension and lateral flexion, as well as other posterior and lateral "chain" muscles like gluteal muscles and hamstrings. Often, we have been using a combination of dynamic and static work with multiple repetitions and fairly long isometric contractions [up to 6 seconds]. The idea being to improve the endurance capacity of the involved muscles.
The problem with these observations is that they are purely experience based. It is therefore impossible to ascertain if the exercises were the true cause of the enhanced performance. There could be multiple other coinciding factors in play.
Core stability training enjoys an almost unchallenged spot in the training routines of athletes.
Such training is widely recommended by coaches and therapists, in books and magazines.
In this article I have summarised the highlights from modern science on the effect of core stability training on athletic performance and injury prevention.
Here is a quick review of the take home points.
1 | The evidence is surprisingly scarce
In light of how widely recognised core stability training is, there is surprisingly little evidence to demonstrate that it actually makes a difference to athletic performance (1).
2 | No convincing results in existing literature
The current evidence reports conflicting results with core stability training.
It has been highlighted throughout the scientific literature that a great number of studies investingating core stability training fails to produce any performance enhancing effects (1,4,6). The argument that stability training improves athletic performance appears to be based mostly on assumptions, rather than scientific data.
It is well established that core stability training improves the ability to stabilise the spine and abdomen. However, this ability does not necessarily translate to enhanced athletic performance (6).
The strongest association between core stability training and athletic performance appears to be found in strongly core-dependent sports like golf, baseball and running (1). But, even here the evidence base is rather thin.
3 | No certain injury preventative effect
There are some studies that suggest core stability training might play a role in injury prevention. This is particularly true regarding balance training to prevent knee injuries (6).
For other conditions, the evidence is either lacking or characterised by studies with poor research methodology.
4 | No superior effect on back pain
Core stability training does have a role in back pain treatment. However, several recent literature reviews conclude that core stability training is no more effective for back pain than strength training or general exercise (18-20).
5 | The core muscles are misunderstood
The notion that core muscles can be divided into “global” and “local” muscles by their function is a belief that has proven to have little root in reality (22).
There is no evidence to suggest the need for “deep” core muscles to contract prior to “superficial” muscles, nor that these muscles need isolated training (22).
What is more, there is no evidence to suggest that global strength training leads to imbalanced muscles or compensatory movement patterns (22).
In modern science, it is fairly well established that spinal stability is achieved through a joint effort by the different layers of spinal and abdominal muscles. This muscular activity is highly varied and dependent on the specific movement task being performed (21,29,33).
6 | Lack of evidence is no proof of lack of effect
It is possible that future research will change our knowledge about core stability training.
Until then, cyclists and other athletes should consider if there are other training interventions that with greater level of certainty provides a greater degree of performance enhancement than core stability training.
7 | Strength training is well documented in improving athletic performance
The positive effect of resistance training on athletic performance in cyclists have been thoroughly documented in a great number of studies (37-45).
The positive effects of strength training on endurance performance is likely due to increased muscle cross sectional area and conversion of muscle fiber types (39).
Muscle hypertrophy following up to 25 weeks of strength training allows increased pedaling power without the rider gaining body weight (37-40,42).
8 | Strength training is proven to prevent injuries
Meta-analyses suggest that proper injury preventative training can reduce the number of sport-related injuries by 2/3 and cut the number of overuse injuries in half. Of the training methods examined, strength training has proven to yield the greatest effect (47).
Strength training can be safely applied by young and old alike, as long as the training regime factors in the athlete’s level of conditioning and a reasonable progression is applied (46).
9 | Perform resistance training with global and sports-specific movements
Athletes are recommended to perform global exercises with high resistance on a stabile surface. Using free weights for resistance are often suggested (6, 22).
These exercises should mach the movements of your preferred sport as closely as possible (51).
For cyclists, this include squats, leg presses, standing hip flexion and ankle plantar flexion. These exercises can also be modified for training out of the gym with simple accessories.
10 | Some athletes might still want to perform core stability training
Certain groups of athletes might still benefit from core stability training. These include young athletes, elite riders, injured or underperforming athletes.
A final word…
It is not my intention to deprive anyone of the joy of doing core stability training. If you experience this as beneficial, do make sure to continue doing it.
However, you might be seeking training methods to ensure the greatest possible performance gain per training hour. If so, you might consider replacing your core stability exercises with strength training.
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