Sunday, January 6, 2019

How Fast Should I Squat?

How Fast Should I Squat? 
by Brogan Samuel Williams (2018) 

Have you ever heard someone ask "Why do you bounce in the hole of the squat?" 

Which gets the internet gym bro response of "Stretch reflex, bro." 

Today we are going to take a closer look at the ideal squat tempo, some common myths, and drill down on the importance of tension, tightness, and stability when squatting.

I try and write these articles to ultimately help people . . . I want to see people move better and continue to stay healthy and strong for longer. I enjoy covering these types of subjects because these topics are either commonly misunderstood, or there is just a lack of quality information compiled, understood, tested, measured and articulated in a way that everyone can benefit from. Today once and for all, we are going to discuss the supposed benefits of a fast squat versus a controlled one. My goal is that you will self-evaluate your own style after reading this article and find a way to maximize your technique and promote longevity. Let's get into it. 

This is What We Will Cover: 

1 The Prime Movers in the Squat
 - A. The Prime Movers
 - B. Traditional Anatomy
 - C. Lombard's Paradox

2) Why Squat Fast
 - A. The Stretch Reflex
 - B. The Stretch-Shortening Cycle
 - C. Momentum
 - D. Rate of Loading
 - E. Less T.U.T. (time under tension)

3) Why Squat Slow
 - A. Loading Tension/Tightness
 - B. Maximizing Stability
 - C. Technical Proficiency
 - D. Injury Prevention

4) The Perfect Approach to Squat Tempo IMO
- A. Tension Over Reflex
- B. Control Over Momentum
- C. Squat Tempo

5) Conclusion

1) The Prime Movers in the Squat

First we need to have a quick lesson on anatomy and biomechanics. 

 - A. The Prime Movers: 
 - Gluteus (Gluteus maximus, Gluteus medius, Gluteus minimus).
 - Quadriceps (Rectus femoris, Vastus lateralis, Vastus intermedius, Vastus Medialis). 
 - Hamstrings (Semitendinosus, Semimembranosus, Biceps femoris). 

These 3 groups of muscles have a unique relationship when functioning together to perform the squat movement alongside a series of synergist muscles and stabilizing muscles which also aid in the movement. 

 - B. Traditional Anatomy: 
You see, traditional anatomy would indicate that for the quads to contract efficiently in the hole of the squat, the opposing antagonist (hamstrings) would have to fully relax - and similarly for the hamstrings to fully contribute to hip extension, the antagonist (quads) would have to relax to allow that contraction to occur. This is the basic principle of agonist VS antagonist and is used to describe the functionality principles of our muscles. 

- C. Lombard's Paradox: 
The Lombard's Paradox describes a paradoxical muscular contraction in humans where the hamstrings and quadriceps contract at the same time, despite being an antagonist to each other. If you don't believe me, squat down right now and monitor the contraction of your quads and hamstrings. Interested? 

Both are contracting in knee/hip extension. This is primarily because a quad muscle (rectus femoris) and all of the hamstring muscles (semitendinosus, semimembranosus, biceps femoris long head) are biarticulate muscles, meaning they contribute to both knee flexion, extension and hip flexion and extension. 

The rectus femoris not only extends the knee but flexes the hip, while the hamstrings not only extend the hip but also flex the knee. In the bottom of the squat, while the rectus femoris is stretched at the knee and shortened at the hip the hamstrings are shortened at the knee and stretch at the hip. Now please keep in mind we are not literally meaning the muscles are exclusively stretching in one area as a muscle belly contracts globally across the muscle, but we are using this terminology more as a general idea and guide to how the muscle is reacting and being stretched or pulled and from which point and direction.

During the squat, your gluteus are exclusively working to extend the hip and the other three quadriceps muscles are working to extend the knee however the rectus femoris and hamstring muscles are working together by creating stability for maximal force production and redistributing of force to the moment arm requiring it the most. These muscles all work in synergy, together creating force through maximizing stability and muscular contraction. So keep that in mind below as we begin to discuss how these muscles react when under certain stimulus and we define the best way to squat.

2) Why Squat Fast

A. The Stretch Reflex:
What is the stretch reflex? The myotatic reflex is a neurophysiological response to a stretch stimulus applied to a muscle. You see, we have these sensory receptors in and around our muscles. These receptors initiate a mechanism within our muscle fibers called muscle spindles. When a stretch stimulus is applied to the muscle, the spindle communicates by sending an impulse to the CNS which results in a response to muscle contraction. This communication is between the muscle spindle and the spinal cord so generally occurs very, very quickly, with most data suggesting within milliseconds. Using the proprioception system, this prompts your body to create a muscular contraction directly after the muscle itself has been stretched. The Stretch Reflex is known to be primarily used by our bodies to prevent muscular injury or tearing, as well as aiding in correct posture and force production. So what does this have to do with Squats?

Well, by increasing speed into the hole of the squat you are sending your large, strong, prime mover muscles into a stretched position - the gluteus are stretched, the hamstrings are stretched at the hip, and the quads are stretched at the knee joint. This then fires off neurological impulses to return the stretched muscle to its normal position.

For years lifters have tried to take advantage of this physiological mechanism to create more force output with the squat. Some data shoes that this reflex not only causes the muscles involved to activate but it also prompts the CNS to recruit and engage supporting synergistic muscles to aid in the restoration of positioning for the stretched muscle and even send an impulse to your antagonist sensory receptors to relax.

B. The Stretch-Shortening Cycle (SSC): 
Now, the Stretch-Shortening Cycle is a bit different . . . it is a global term used to describe a reaction that occurs to your muscular-skeletal and physiological system when you perform a movement that requires an eccentric and concentric contraction. So, the Stretch Reflex is more of a neurological prompt and the SSC being the actual muscular response to being stretched while also incorporating aspects of the stretch reflex. The SSC refers directly to a physiological counter-movement when performing certain exercises like squatting, sprinting, and jumping. The pre-stretch during the eccentric load is thought to have a direct effect on the concentric muscular contraction and force production and is said to allow the lifter to produce more force and move quicker than he could if he were to perform the movement from a static position.

Although there is some controversy around the reasoning of this, let's look at what is commonly believed to represent the SSC:

1 - The Storage of Elastic Energy Within the Muscle:
Elastic energy is stored in the muscle throughout the eccentric portion of the lift. That energy can be used to contract the muscle and produce force during the concentric phase (however, this energy will dissipate into heat if not used straight away).

2 - The Rate of Loading:
As discussed above, muscle has elastic properties, thus lending itself to the argument that for every action there is an equal and opposite reaction. This means that the faster you extend the muscles, the faster they want to return the muscle via the elastic energy stores and muscular rebounding momentum.

3 - The Neurological Prompts That Incorporate the Proprioception System:
This includes the sensory receptors of the muscle spindle the neurologically activate the stretch reflex, resulting in the contraction of synergistic muscles.  

By utilizing all these things, data shows you can increase athletic performance with plyometric, ballistic training, jumps, and body squats. However, I would suspect that it has some but little carry over to the loaded squat. In fact, let's take at the extent these muscles are 'stretching'.

The gluteus are in a full stretch at the bottom of the squat but don't primarily aid in the bottom of the squat - knee extension does - hip extension is for later. The hamstrings are shortened at the knee and lengthened at the hip, while the quads are lengthened at the knee and shortened at the hip . . . meaning that to achieve a full stretch from these two muscles you would have to perform a totally different movement than that squat - the squat, in theory, is only providing half the amount of stretch that a specific muscle is capable of. Giving us only half the amount of stretch reflex and SSC.

C. Momentum:
Linear momentum is the mass multiplied applied by the velocity of an object. When we descend into a squat we often find that lifters can experience an extra "pop" out of the hole by loading their calves into the bottom of their hamstrings and then launching off them, building momentum out of the hole. You will also see lifters shove that shove that eccentrically gathered momentum into their knees as they rebound out of the hole. You see their knees travel excessively forward and then drift back into a normal position as they maximize the momentum gathered to drive them through their sticking point.

D. Rate of Loading:
As discussed above, our muscles have an elastic type quality to them that allows them to be stretched then creating a returning force to the neutral position. The muscles are not always best represented as a rubber band, but as a spring - the increased rate of the eccentric load directly equals the force applied to the concentric contraction. The Stretch Reflex is not only a force contributor but an injury preventer, a key principle being that the muscle will try to respond at the same rate at which it has been pushed. The reflex itself is to avoid the muscle being over-elongated or stretched to the point of injury - so the force that is placed on the muscle needs to be met with an equal responsibility for this injury-avoiding mechanism to function properly. This can often be brought up when discussing the stretch reflex and evaluation of the force that is returned on a concentric contraction.  

E. Less Time Under Tension:
Any further time under a maximal amount of load will result in a higher rate of fatigue to the muscle. In the traditional sense, we use time under tension (TUT) to create muscle trauma, tear down muscle fibers, stimulate muscle growth and force blood into a muscle. The longer your muscle is under the tension the more that muscle fatigues, as well as the energy source that is supplying the movement (buildup of hydrogen ions, metabolites, and acidity in the muscle). This traditional concept most definitely applies to a squat, but furthermore, we need to discuss the loss of elastic energy if we are performing a 'pause squat'.

Once you hit the required depth you need to explode into the concentric contraction. Every second you spend in an isometric or static contraction leads to a weaker and weaker launching position. Meaning, if you wait around t the bottom you will not only begin to experience muscular fatigue but you will begin to burn through your elastic stored energy. Keep in mind we have not discussed the rate of force or aid the SSC and SF has on a loaded squat.

3) Why Squat Slow?  

A. Loading Tension/Tightness:
It is absolutely necessary for an athlete to understand the benefits of tension and tightness when performing compound movements. Maximizing tension not only promotes safety within the lift but helps the production and transfer of force throughout your body. Force is often emphasized through tightness, tension, and stability.

Breathing and Bracing:
One of the many things I feel is overlooked and misunderstood in general is the benefit and importance of Breathing and Bracing . . . not to mention it's always the first thing that goes out the window when someone decides to drop in and out of the hole at a rapid pace.

The idea is to produce as much force as physically possible when performing the squat, and we do this by applying tension and tightness in the correct areas that become compromised during the lift, from the foot to the floor, the knee to hip positioning, posterior tightness, and torso rigidity.

In my experience, the breathing and bracing efficiency tend to be the first thing that is lost when someone is squatting too fast or bouncing out of the hole. First, let's look at why breathing and bracing are so important.

To create, transfer and withstand maximal amounts of force efficiently you need to:

 - Create the best biomechanical leverage possible with your anatomy. 

 - Load the correct prime movers.

 - Provide adequate muscular tension for the force to be transferred without technical breakdown.

 - Provide adequate tightness through breathing and controlling your air for the force to be transferred without technical breakdown.

 These fundamentals are built on the premise of tension and tightness which is created through breathing/bracing.

 - You can start in the best biomechanical position but will struggle to maintain the correct positioning during the lift if you are not maximally utilizing your breathing/bracing.

 - You can load your prime movers to start with but due to lack of tension and tightness you begin to recruit other muscles to provide stability due to poor movement patterns, rather than neurologically focusing on recruiting as many fibers as possible from the prime movers.

 - You cannot provide and transfer maximal contractile force efficiently and safely without adequate muscular tension to help transfer or withstand that force.

 - You cannot provide and transfer maximal contractile force efficiently and safely without adequate tightness produced by your breathing to help transfer or withstand that force.

Breathing and bracing is another tool that should be utilized to maximize performance. However, I find that lifters who move quickly often find it harder to contract the right muscles, control their breathing and master their coordination. I always coach my athletes to SLOW DOWN which allows them more time to make that mental connection to what they are trying to achieve.

This is why, in my opinion, squatting slower allows you to better practice and perform your breathing and bracing routine.

The Eccentric Loading:
We can utilize the time during the eccentric load to create tension where we need it most. I often teach my lifters to use the negative part of the movement to store the tension into the appropriate muscles like a spring. We know the principle of elastic energy/SSC's physiological muscle response is at work and we can utilize this when descending into the squat. The Stretch Reflex and SSC response is said to occur within milliseconds, which would mean that you run the risk of losing energy as heat if you were to pause the rep, however, we are talking about benefiting from both sides here - utilizing the eccentric for stability, specific loading of tension and enhanced coordination whil still achieving a great reflex/muscle response out of the hole of the squat. It's about training the proprioception system to recognize when to send those signals to the sensory receptors to kick the prime movers into action.

So can we give you a specific number for how long we can eccentrically load the squat or pause at the bottom? The data is limited for this, however, we can theorize an answer by analyzing a study of a similar physiological action, the static stretch. A study recently showed that the greatest alteration to a muscle when being stretched is between 15-30 seconds. So somewhere between the initial stretch and that 15-second mark your body's stretch reflex wears off and the stored energy 'allegedly' burns off as heat. Can we give a specific number? Well, no. But I would say that the energy-storing properties or a muscle last longer than a few milliseconds and most likely can be used within a few seconds and also can/do contribute to force production during a squat - how much, we just don't know for sure.     

B. Maximizing Stability

I recently wrote an article of Active Foot Stabilization (AFS) and had a massive amount of positive feedback. I find that people often overlook some of the most important aspects of lifting. In this case, most lifters would maybe focus on knee position and keeping their chest up, with maybe a little breathing into their belly for bracing while completely overlooking stability from the foot to the floor. Wow.

It all begins at the floor and a weak link there will compromise stability all over the body. So, I teach stability at the floor and move my way up, sometimes fixing the valgus knee or hip shift purely by teaching stability. It is the exact same when squatting - stability has to be prioritized to maximize force production and safety during the lift.

We can do this by:
 - stacking our joints correctly in the starting position.
 - breathing and bracing.
 - implementing active foot stabilization.
 - using eccentric tension.
 - correct movement patterns.
 - slowing down the eccentric on the squat to enhance coordination.

C. Technical Proficiency

When performing complex barbell exercise, technique HAS to be the priority. But we know that, right? You know, chest up in the squat . . . back flat on the deadlift . . . tuck in your elbows on the bench? Well . . . it's a little more complicated than some overused, not lifter-specific cues.

The technique is primarily to do with motor pattern and coordination.

It takes time, it takes weeks, months, years of blood/sweat/tears. Well, maybe I'm exaggerating a bit but you get my point. We train multiple times a week, working not only on getting stronger but also at increasing our technical proficiency.

It takes time and many sessions of a coach's evaluation, or self-assessment with feedback/dues or instructions on how to better ourselves - it's a long process. I'll be honest with you. I trained very hard for a GPC Nationals event one year and was really excited to squat a massive amount of weight. Leading into the prep I incorporated some new teachings to maximize my technique and I removed the fast bounce and hoped for the best squat. Well, even after months of preparation when it all came down to it I was nervous and dive bombed . . . yep, I dropped that squat low and fast! I was so annoyed at myself for all of a sudden changing my whole technique back to what I used to do. Man, technique can be really hard and can suck sometime.

A lot of the lifters I see in the gym and online generally exhibit poor form, so my advice is . . . slow down the squat to better focus on stability and coordination. Even World Champion powerlifter Stan Efferding has said that he slows down his squats to keep himself from falling over.

Todd Hardgrove, movement therapist, explains, "To move slowly and gently is to allow yourself time to approach movement in an exploratory and curious manner, and to put a great deal of attention on the subtle details of the movement. Becoming more coordinated is essentially a matter of rewiring the neural circuits that control movement, which is an example of a very fashionable process called neuroplasticity. According to Michael Marzenich and other prominent neuroscientists, attention and awareness are major preconditions for neuroplasticity to occur. In other words, your brain is much more likely to get better at a certain activity if you are paying close attention to doing it. Slow movement can help your ability to pay attention to exactly what you are doing when you are doing it.

So there you have it! A slower squat leads to more coordination/stability and most likely better technique.

D. Injury Prevention

We use many tools in the toolbox to enhance performance and avoid injury. When under maximal amounts of load you DO NOT want to be dive bombing or moving faster than your body can handle. Lack of stability, tension, and tightness during the squat can lead to injuries. When momentum is accumulated and force is being produced it can be expressed in many different ways. We teach full body tension to keep this momentum and force applied to the correct muscles, avoiding power leaks throughout your setup. When moving fast you are more likely to make a motor patter error, resulting in the wrong muscle and mechanical movements to overcompensate and finish the lift.

When we squat too fast and lack tension/tightness and stability we can often see:

 - the knees caving in.
 - hips shooting back.
 - chest falling forward.
 - lateral hip shift movement.
 - shoulder instability and excess pressure.
 - excessive elbow pressure.
 - lumbar flexion.
 - foot to floor instability (medial pronation, foot movement, etc.

4) The Perfect Approach to Squat Tempo

Based on my own personal athletic performance, my experience with my own clients, athletes, the study of biology, anatomy, biomechanics and information stated above, I'm going to lay out the most efficient squat tempo, and why, in my opinion.

A. Tension Over Reflex
The raw squat requires an incredible amount of full body tension/tightness and stability to be created by the lifter to insure safety, longevity, efficiency and strength/power in the lift. Spend more time focusing on activating the correct muscles to lift the weight which in return will produce greater hypertrophy and strength results. Use your breathing and bracing to minimize risk and maximize stimulus - induced to the correct muscles that you need to grow stronger to blow up your squat.

A reflex is a neururo-physiological response, a reaction caused by movement. Are you going to rely on this to increase your strength? It can help you initiate muscle contraction but in my opinion it's a very small piece of the pie. The reflex is another tool, so use it in proportion to the results it produces. You can utilize the stretch reflex and train your proprioception system to fire with a controlled eccentric squat.

You don't need to sacrifice tightness, stability, safety and technical efficiency in the name of a reflex or "momentum".

B. Control Over Momentum
Momentum may be an option for those who are trying to squeeze every last kilo out of their competition squat, but at what cost? Relying on momentum to squat can have its benefits, but it absolutely has to come under the umbrellas of CONTROL.

Controlled and planned momentum may provide some benefits for you but it also comes with risk. Rather than relying on an external force to carry you through the motion, we should be focusing on maximizing the performance of our engine room, the muscle fibers! There are many different ideas and perspectives out there on this topic, but in my opinion all beginners and intermediates should be learning how to properly contract and utilize their muscles when performing compound lifts, which means taking the time to streamline their technique and control their body, not throwing it around in hopes of a few extra kilos on the bar.

C. Squat Tempo

I can hear it now . . .

"I hit the hole so fast bro to get more rebound."

Yeah . . . okay bro.

Squat tempo has its own place in the pie of 'squatting' but ultimately what is the right answer?

After all the information we have just covered, let me break this down very clearly for us all . . .

SQUAT FAST - more momentum, rebound and reflex which can potentiate into more weight lifted.
SQUAT FAST - more instability, lack of technical consistency and efficiency, harder to maintain bracing, higher injury factor.

SQUAT SLOW - more controlled, better technical efficiency and overall stability, easier to maintain  correct breathing and bracing, proper muscular contraction and engagement, more tension and tightness throughout the setup and movement and less likely to cause injury.
SQUAT SLOW - can potentially take longer to train proprioception system, minor loss of power through lack of possible momentum, rebound and stretch reflex.

So, what about a 3rd option? One that incorporates the best of both worlds?

A controlled yet confident quick squat that prioritizes breathing/bracing, torso rigidity, overall muscular tension, and engagement and setup stability while hitting the hole with confidence and speed through streamlined technique.

5) Conclusion

In my opinion, the raw squat is more reliant on efficient breathing and bracing, stability and mechanical proficiency than a neurological reflex or a physiological muscular response to being stretched. However, the stretch reflex and the SSC [Stretch Shortening Cycle] is a proven physiological response and can be used when squatting. You can still maximize the force production properties of the Stretch Reflex/SSC and not sacrifice the other important factors above by eccentrically loading in a controlled but fast manner throughout your descent. By training your proprioception system you can explode out of the hole, maintaining the best physical and mechanical positioning based on tension, tightness, and stability and still get some use of the Stretch Reflex/SSC without bouncing or using excessive amounts of momentum which provide too much risk. For beginners, I would suggest keeping your squats slow and controlled until you become competent with your mechanical positioning, breathing and bracing, and bar path. I would then encourage you to explore the benefits of a faster squat tempo.

So there you have it. I hope this information helps you make better decisions when considering how you want to SQUAT.    







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