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Maximum Speed Practical application Problem solving Strength training Strong legs makes their own path

Strong legs makes their own path pt 1 – Does it really take two to tango?

A conservative is a man with two perfectly good legs who, however, has never learned how to walk forward.

Franklin D Roosevelt

Stronger legs is associated with enhanced general sports skills as rate of force development and external mechanical power expressed in movements like jumping, sprinting and change of direction as well as specific sport performance. It is also enhanced with decreased injury rates. Since athletes started accompany their on field training with exercises in the weight room, the undisputed king of the movements to get stronger legs has certainly been the squat.

The Hegelian Dialectic holds that conventionality, staying within the box of conventional thought, gives rise to a thesis. Every thesis eventually gives rise to an antithesis, a challenger: a rebel arises, assaulting the conventional barricades of the thesis. A fight ensues and out of the ashes rises a third idea, a synthesis, resolving the conflict, and becoming the new normal, the new thesis.

It’s hard to find more obvious examples of this than when Mike Boyle stood up in 2009 and said “don’t do squats anymore” declaring the first and foremost tool used to create strong athletes is obsolete.

I am no cultural anthropologist, but it seems to me that this very moment was important in order to create the rift between the functional movement-crowd, who laugh at those training like powerlifters, and the old-school weight lifters rolling their eyes when seeing the guys doing the split squats.

Obviously the initial idea was met with a backlash, and both sides have since then sharpened their arguments. And the main arguments for single leg exercises goes something like this

  1. Most sports are played on one leg at a time, hence they are more specific and should transfer better to sports performance
  2. The requirements of proprioception (the sense that people have of knowing where the parts of their body are) and core stability is greater when doing single leg rather than double leg variations
  3. Single leg exercise balances out imbalances in strength between sides of the body, as you can no longer shift more onto your potentially stronger side making up for the lack of strength of your potentially weaker side.
  4. Less stress placed upon the lumbar spine, decreasing the risk for back injury

Whereas the bilateral (double leg exercise, like the squat) proponents line of arguments would be similar to the list below

  1. You cannot load the single leg lifts like you can the double legged variations.
  2. Specificity and mimicking is not the same thing: the goal is to strengthen a function, regardless of how it looks.
  3. The loading on the spinal column might be less in absolute terms for single leg exercises, but it is also both asymmetrical and done with less balance.

Basically the first arguments form both sides is regarding specificity and transfer of complementary training into sport performance. The main point for the unilateral-side is that regardless of the lesser overload being put on the athlete performing the single leg exercise, the movement being more similar in the joint-synchronization, the coordination of movement between body parts, to what he or she does on the field should yeld more carry-over of what capacity is increased.

Car analogies are popular to use with this line of reasoning, such as that if we “increase the engine while still driving on bad brakes and tires” we would still not be able to express the strength of that engine. This strategy seeks to increase the robustness of the movement pattern by keeping them contextual, so that the system as a whole will shift towards a greater force production.

And single leg training would potentially allow for more overload of the legs, as less core strength is likely to be required when moving lesser loads. Removing this as a limiting factor might just build stronger legs.

The comeback would be that this still limits the possible overload that you can place on the system as a whole. And because of this you would limit both the mechanical loading on the whole muscle and tendon, as well as not stimulating the central nervous system and synapses, thus missing out on neural aspects of improved force production.

Both arguments are sound to me.

Next, there is the argument of structural balance, leveling the differences in mobility and strength between sides of the body, from training one side at a time. Which is an argument that both “sides” share to some extent, for neither is advocating to train muscles fully in isolation. And with compound movement a synchronized chain of action is strengthened while being carried out.

Something that could be said against the idea to make all athletes symmetrical is that the fastest man we’ve seen so far, Usain Bolt, showed that you could be running with an asymmetrical stride (from scoliosis and a right leg a half-inch shorter than the left) and still be the apex predator of the track and field.

So while addressing all asymmetry seems overly categorical, when faced with pain or dysfunction we need to react and remedy somehow. And when the hands or legs are not connected by a barbell, or one side is trained at a time, more degrees of freedom are appears. This could good for the people with dysfunction in the hip or shoulders, because that means that they can let their body “solve the problem”, finding ways to move without pain.

So, again, both arguments would be sound depending on the context.

Finally, the loading of the spine is usually mentioned. Lesser loads on the spine and the injury risk should decrease with it. Yes, but one would not want to spare the spine from loading altogether, because this would not build the muscles needed to stabilize the spine in sports and life. So the truth would seem to be somewhere in between to much and too little. If you tolerate high loads, then that might be better. And certainly, as we shall see, lesser loads calls for higher volume of training, which translates into something that is also a possible cause for injury: fatigue.

The argument of bilateral force deficit, that the total amount force produced during two unilateral contractions is greater that the force produced a single bilateral contraction, seems quite irrelevant as it seems that both types of training can improve strength to a similar degree, but with specificity of movement yielding the most benefits (an argument already made).

When it comes to training strength there is multiple ways to skin the cat, but all of them includes sets of exercises that are completed close to, or to the point of failure to work the largest motor units and to induce sufficient mechanical and neuromuscular stimuli. This means we could be using either moderate loads and higher number of repetitions or heavier loads coupled with a lower number of repetitions.

But by keeping volumes lower and intensity higher, we would be where we need to be from a strength point of view, and never tired from too much complementary training. Which could render us unable to do well on the field where true specificity, and true speed, is to be found. Excessive fatigue alter movement mechanics both in and outside of the gym, having implications for training practice and injury risks. If we are making our athletes unable to train at the speed demanded from them come game time we are at best not setting them up to win, and at worst they are not able to react quickly enough to unexpected events rendering them susceptible to injury.

As a general rule: chasing maximal neural drive and velocity in each lift enables us to get more out of less. With more stability and balance, as you get standing both legs, you get just that which should seem to favor double legged exercises.

But irrespective of exercise used movement mechanics are changed when approaching that point of failure. Specifically a reduction in moment at the knee made up for with an increase at the hip and the lower back. And when this coordination in movement between body parts is changed we are no longer being contextual and we are now overloading muscles, rather than the desired movement.

The triple extension, the synchronized opening of the ankle, knee and hip, that is so important in sports because it allows to produce maximum power against the ground, is compromised when the knees extend ahead of the hips. This could even lead to altered extension mechanics, if we do it often enough, something deeply undesirable for most athletics.

So, heavy weights coupled with intent might offer improved force production from central stimulation – but when doing so also changes joint synchronization and muscle coordination. This seems to me very problematic for heavy strength training. At best meaning the capacity will not carry over as well as it could to the field, and at worst actually decreasing sports performance.

We are faced with a dilemma where there is no correct choice to be seen.

  1. Overly fatiguing athletes is just not ok, they must be able to perform their best in their sport specific sessions.
  2. Double leg strength movements might be less intentional, but suited for heavier loads coupled with a lower number of repetitions – minimizing fatigue – but might because of that disrupt joint-synchronization.
  3. Single leg strength movements, while more intentional, are nicely suited for moderate loads and higher number of repetitions. But when doing that, the repetitions up until those last ones are neither working the largest motor units nor giving much neuromuscular stimuli. But causing quite a bit of fatigue. And when we get to the “money reps” we still have the drawbacks of the altered movement mechanics.
Disillusioning, but we shall try to find the best way forward in the next part.
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Maximum Speed Practical application Problem solving Strength training Strong legs makes their own path

Strong legs makes their own path pt 2 – Finding your balance

”The aim of physical preparation is to go beyond the level of motor ability that can be achieved by the sole practice of the chosen ability”

Michael Pradet

The only training that is certain to stimulate exactly the parts that makes up the full competitive movements and pathways for performance are training that is consisting of exactly those movements, performed in the same context as in competition. That is, doing the actual sporting events, and this is where training should start and what should always be included in a training program. But there is reasons for not only training the sport in specificity, such as the need for overload and variance. At some point we just can’t get better from doing the sport alone.

Training should certainly be designed to provide similarity when it comes to muscle action, cooperation, joint movements and energy systems as the movements performed on the field in the sport. But sport specific training should not only focus on physiological aspects of adaptation. Movement control needs to be universal because, possibly, of limited storage capacity for “motor memory”. Regardless of “size” of the memory, storing fixed sequences for all possible movements would certainly result in “choking”, because that would mean that you would have to find the exact match for the situation at hand before acting.

Instead movement seems to be structured by “patterns” so that the central neural system can let the body self-organize to a certain extent, and therefor fulfill both the need for speed to action and ability to handle variation in the environment where movement is performed. The same patterns would allow us the flexibility needed, for instance, to run both on grass and in sand.

Also, strength is not an isolated quality, but an integrated aspect of eventual performance. The ability to use a high number of muscle fibers in order to produce a a lot of force depends on how skilled or trained the athlete is in the specific movement.

There is a sort of “parental control” at work in order to protect the body from forces it is unsure that it can handle. A 100m sprinter can not be allowed to produce the same amount of force in a football game as when he or she is on the track. A football player have practiced to absorb the force produced when faced with the need for a sudden change of direction. A sprinter, who can produce force something like 6 times the bodyweight per leg, have not and if allowed to express this force on the pitch it would mean to risk serious injury

To cope with this, force production is linked to related movement patterns, not only in similar physical structure but also in similarity of sensory patterns (seeing and feeling) and intention. Exercises that are very specific to the sporting movements are very specific in all of these, but hard to overload without changing these sensory and intentional qualities. Movements that are easy to overload, are also very different and will therefor “unlock” less force production to use in the field of the sport.

This line of thought concerning the role of coordination and learning in order to express force and power is outlined to great detail in Frans Bosch landmark book “Strength Training and Coordination”. In the book this dichotomy between specificity and overload is neatly presented in the image above, as the central/peripheral model, a problem that all coaches have to deal with. Then he goes on to notice that most inexperienced coaches spend a lot of time in the ends of the model, which is a safe starting point, but advising that more time should be spent in the middle zones of the model. A zone where both some similarities when it comes to those sensory and intentional qualities can be included, while still also offering some overload when it comes to force production of the muscles.

“Do you want to be strong, or do you want to lift heavy weights, they are not necessarily the same”

Jerome Simian

Last year I had the opportunity to listen to a presentation from the French coach Jerome Simian, who thinks in similar terms when it comes to movement quality. Jerome, who is the coach of Kevin Mayer – world record holder in Decathlon – talked about the importance of technical movement, the fundamentals of human movement that are common to all efficient movement patterns. He gave the advice that acquiring the ability to do a strict, perfectly coordinated, full squat will help improve the hip, pelvis and spine relationship. The ability to synchronize the opening and closing of these joints in order to maintain balance is one of the fundamentally common efficient movement patterns. The main point being that there is nothing to gain for an athlete, other than a powerlifter perhaps, in sacrificing perfect form for more weight on the bar.

Actually, too much time spent during strength training on movements that are not similar at all to the sporting movements, or performed in a synchronization between joints vastly different from the sporting movements can actually lead to a lowering of the performance in the sporting. This negative transfer can arise due to changes in coordination (from changes in muscle action and cooperation) or too much fatigue, no matter how much the athlete can improve the lifts used in training. And just because there is no general answer of “how much is too much” (and if there were this would also change with time), it makes good sense to prioritize keeping track of improvements in the sporting movements rather over whatever kilos someone can squat.

But back to the question regarding single leg versus double leg and heavy versus light weights. Both science and practice has repeatedly shown increases in various measures of sports performance with the inclusion of bilateral exercise in the training program. But single leg training too has been shown to do that. A caveat being that for single leg training this has, as far as I know, only been studied in untrained subjects. My own experience however is that, if done heavy enough, single leg training is also a potent stimuli for strength.

Learning from coaches like Frans and Jerome we start to get a good idea that we would like to

  1. Keep movement somewhat similar in movement patterns and stimuli
  2. Overload as much as possible while satisfying rule #1. Large load means larger neural adaptation and higher percentage of muscle fibers being recruited.
  3. But do not let the main movement mechanics break down or change during the set

Similarity should be sought in producing force using the same muscles, in similar directions. That means that I would argue for single leg movements for developing maximal leg strength for sports played on one leg (cycling, team sports, track and field, racket sports, etc) and double leg movements for those that have movements performed symmetrically (power lifting, weightlifting, CrossFit, etc). Similarity in sensory and intention in this context is obviously hard, but means mostly to have a clear, and similar, beginning and end of the movement.

Further, I would generally do these movements heavy: 1-5 repetitions per set, and I would not do as many sets as the athlete could do being cautious of unnecessary muscle-damage.

(Nothing should ever be set in stone and obviously what the athlete in front of me enjoy the most will also matter when making these choices, but we are talking general rule of thumb here.)

Still the main problem is that for “the reps that count”, the ones where we have to use our strongest muscle fibers, the mechanics are likely to change. But I think that there is a solution: a “hack of the system” to duck the problem with lack of balance affecting the movement mechanics. Regardless if this mechanical change comes from fatigue and/or intensity.

Hand assisting the movements allows you to provide just so much balance so that the movement mechanics are kept the same (maintaining good movement), but not too much to provide sufficient neuromuscular stimuli. Further, the help maintaining stability can be controlled and increased when fatigue accumulates. This might decrease the load placed on the body slightly, but – and this is important – to exactly the extent that you are capable of handling that very moment.

In many ways it seems to provide a perfect compromise in order to build maximum usable strength! So how could this look when it comes to strengthening the legs?

My two favorite movements are for this is the hand-supported split squat fathered by Fred Hatfield and Cal Dietz performed with the safety-bar.

The key is to not allow the hips to open quicker than the knee, and slightly “leaning into” the support makes this possible with quite heavy weights. This also provides the feeling of “going forward” which might provide som similarity to the sporting movement from a sensory information standpoint. Clear and distinct final position is coupled with an equally clear starting position, that could be varied with elevation of front or back foot.

If you have access to a flywheel training device then you can replicate my next favorite exercise that we call “old man with a stick”, which is similar in design just that using the belt makes it easier to really “go for it” with less possibility for a missed lift. And with the sticks it’s also not possible to “cheat too much”.

I quite like the relative balance of the trap bar and use that quite a lot too, but apart from that I haven’t used many other movements for the maximal strength of the legs (for sports played on one leg) in quite some time.

Fewer movements and less volume on “the far end” of overload leaves more time to work that “middle zone” that Frans Bosch talks about in his central/peripheral model. Movements that might not working maximum force production but still overload force produced and with more related movement patterns. Movements as (weighted) jumps, throws and weightlifting derivatives, which I think adds so much much both to transferrable force production and to include sufficient variety in training to avoid the stress of boredom and monotony.

Just a small selection of the exercises that could be done in this “middle zone”

Since implementing this line of contextual thinking for my athletes concerning their maximum strength work I’ve seen very good results on the field while doing way less of it.

I think it’s very easy for coaches to get stuck “chasing kilograms on the bar” and ending up thinking that every athlete should commit to a “starting strength” type of power lifting program in the weight room, where in reality probably not many should. A more efficient program might yield better transfer of force production, but still free up time for specific work in the gym or on the field.