Air Bubbles in Shoes…Do They Cushion Impact Forces?

Growing up I fell in love with basketball. I’d race home after school to go to the park and just get lost in shooting shot after shot. As I grew older I started noticing all the different current trends and fashion in shoes and what kids wore on their feet. Everywhere I went kids wore Jordans, Nike Shox or any shoe that had some kind of air bubble. These flashy looking shoes were all the rage. In my young fifteen-year-old mind I thought it was the greatest thing since sliced bread and wanted to get a pair to show off. The “Walking on Air” vibe was certainly brilliant marketing to sneakerheads trying to display luxury built on comfort. During gym class, I’d play with these type of sneakers more and more and I even competed in my youth group basketball with a set of Jordans VI that had the air bubble in the heel. I can remember what I said to myself almost every time I slipped those bad boys on. “These feel narrow and when I land it feels like something is off but who cares”. I remember how awkward it felt to move and run but I didn’t want to make excuses thinking “Hey it’s not the shoe that makes someone great its the way they play so” and so I continued to wear them. Plus I just really cared about playing no matter what I had on my feet. I continued to compete despite slipping and sliding awkwardly with them on.  That overlooked feeling would soon come to a head when during my final youth group championship game I sprained ankle severely the first two minutes of the game scoring a layup. I landed on another person’s foot awkward as every person who sprained their ankle knows but I tried to reverse the motion trying to get my balance back toward the midline and compensated further injuring the other side as well. But, hey, I sprained it while scoring for my team so that shows dedication right?

This injury made me reconsider what I wore on my feet and even how I moved. This also led me to appreciate the human body and appreciate all the complexity that goes into movement.

David Forland, Nike’s director of cushioning innovation, changed Nike’s approach during the late 80’s in order to sell more sneakers. In order to sell the sensory perception of walking on air, Forland inversely made each model having a greater volume of air than the last one and decreasing the amount of foam. He stated that “Foam breaks down; air doesn’t”. All that fancy air bubble unit is just a polyurethane pouch filled with inert gas and they just connect it to the foam sole. They obviously had major success since some of these sneakers are some of the most lusted after sneakers for decades catering to many populations of people and different athletes. Here were some of the so called benefits of the MAX AIR

  • Versatile: Max Air cushioning is designed to meet each athlete’s exact specifications of athletic performance
  • Cushioning: absorbs impact forces when the foot strikes the ground protecting muscles, joints and tendons and recoils to protect against the next impact forces. which will protect athletes from stress and fatigue.
  • Durable: provide cushioning throughout the life of the shoes

These are tempting but dubious claims. I think it’s quite a claim to say that a pocket of injected air works for every athlete and their exact specification for their sport. So what works for a basketball player will also work for a marathon athlete?

Image result for square peg in round hole

That’s a perfect example of a cookie cutter approach. A physical therapist and biomechanics expert named Jay Dicharry probably hits the nail on the head telling The Atlantic “Part of the problem is the shoe industry as a whole does a really horrible job of matching footwear to feet,” Sadly this is what good marketing does. It just sells products without any regard to the activity. It’s even dumb easier when you’re able to use star athletes to endorse your product.

While the air bubble certainly revolutionized the sneaker world, does this air cushioning unit really absorb the shock? Unfortunately they don’t do as they claim to and in fact, dampens your ability to feel the ground. This messes with the way you move by delaying the proprioceptive response of the ankle. These air units aren’t absorbing shock not because they aren’t strong enough to resist the ground forces but because it’s robbing you from feeling it all! It’s hiding the input! Add a one to two inches in the heel and it complicates the kinetics of your foot. Here are some studies showing that highly cushioned shoes don’t decrease the impact forces Study 1Study 2Study 3, Study 4 but this particular Study 5 was a big one because it showed that one of the risk factors to ankle injuries were players that wore shoes with air cells in the heel were 4.3 TIMES MORE LIKELY TO INJURE AN ANKLE than those wearing shoes without air cells  The fifth study hypothesis is that the air cells located in the heels of basketball shoes decrease rear foot stability, which may, in turn, increase the risk of ankle injury. I believe it makes sense since the extra air in the heel puts an extra inch or two in your shoe and so now your much higher off the ground which leverages into spraining your ankle easier. Add that you have something that is supposed to act like a pillow underneath your heel which disrupts how you sense the ground below you and you got yourself a problem.

you're gonna have a bad time guy - If you can't feel the ground You're going to have a bad time

Because I like to play devil’s advocate, I tried to find some studies that showed that some high cushioned shoes did decrease the impact of forces. The studies that supported this notion showed a decrease in EMG musculature in the legs Study 1Study 2. While the evidence does support that it decreases the EMG in the musculature, does that truly mean that the impact forces are being absorbed and the shoes are doing their job? I don’t think the EMG tells the entire story. Perhaps the decrease in muscle activation is because your body doesn’t anticipate anything happening and so it doesn’t have to respond. It leaves me with the question of is this perceived safety of muscles not turning on a problem in of itself?

Then there is one Study that flips the notion that impact forces are the cause of injury. In it, Nigg states “A new paradigm for impact forces during running proposes that impact forces are input signals that produce muscle tuning shortly before the next contact with the ground to minimize soft tissue vibration and/or reduce joint and tendon loading. Muscle tuning might affect fatigue, comfort, work, and performance. Experimental evidence suggests that the concept of “aligning the skeleton” with shoes, inserts, and orthotics should be reconsidered. A new paradigm for movement control for the lower extremities proposes that forces acting on the foot during the stance phase act as an input signal producing a muscle reaction”. Here is another Study showing that muscle damps soft tissue resonance at heel strike. Wakeling states that “Muscles generate forces which act across the joints and, therefore, shoe design may be used to modify muscle activity and thus joint loading during walking and running”. The second study in this paragraph shows how the different shoe designs modify muscle activity because each design has specific pros and cons in which it robs how you sense the input and so the muscle doesn’t allow itself to tune in to the forces coming in.

So the body encounters these impact forces and perceives them vibrations. but what do vibrations have to do with impact forces? According to Benno Nigg’s work on Muscle Tuning, the body dampens and absorbs the vibration of the impacts of everyday loads through isometric contractions (Nigg, B.M., Liu, W). So the muscle tuning happens by the muscles isometrically contracting in order to decrease the vibration in soft tissues in joints and tendons. Nigg saw the impact forces as a source of feedback in response to the vibrations. The tuning function of muscle activity (muscle tuning) suggests that impact signals are sensed and the central nervous system responds by tuning, if necessary, the activation of the corresponding major muscle groups, in reducing impact loading during athletic activities (Nigg and Wakeling, 2001). The isometric contractions serve as a pre-activation of muscles prior in order to prepare for impact to the ground. It’s a signal used to detect what’s going on and adjust accordingly with vibration (Nigg,2000). Add the different surface types such as hardwood, concrete and the muscle tuning frequency changes. There was also a study by O’Flynn (1996) that showed the pre-activation changed based on surface ( This muscle tuning is calibrated to the surface in order to control the soft tissue vibrations. If someone was running on concrete the muscle/bone vibration was much higher than running on a soft track. I think we can guess that the muscle contractions are the bodies own mechanism in responding to the vibrations. Perhaps the shoe influences how the body perceives the signals coming in and how to respond. This brings me back to full circle of maybe impact forces are not the problem but maybe it’s the input of the signal that is lost. Also, it makes me think that if the signal is being lost then our feet wouldn’t be able to respond accordingly and so we wouldn’t be able to condition our feet to withstand the volume and demands of the specific sport or activity.

Emily Splichal, the founder of and author of Barefoot Strong, notes that if muscles cannot create enough tension to create the necessary intra-compartmental pressure to dampen the impact force vibrations, the vibrations will default traveling into the soft tissue and bone and cause many issues such as stress fractures and shin splints. So perhaps these air-bubbles mess with the signal because it’s robbing it of the input for the lower leg muscles to isometrically contract so they can respond and adapt to the stress. Wouldn’t it make sense that some of the best athletes and jumpers have exquisite timing patterns to contract and respond to the stress and high volume of jumping?

Image result for vince carter dunking forearm

I’m not sure if this is even close to what’s really happening in our body but it sure does make me think. Here’s a fascinating story about Dr. Benno Nigg working with Cirque du Soleil in 1999 ( The performers were getting Achilles tendonitis and plantar fasciitis injuries and the company was befuddled as to wonder why this was happening. Nigg searched and found that the problem was that underneath the stage were a bunch of hidden beams. The performers had no idea whether they were secretly landing on the stage or where the beams where.  Nigg thought the beams changed the vibration frequency of the above stage and their body couldn’t anticipate what vibrations to receive when they landed. They couldn’t perceive the accurate input when they landed and the volume was taking a toll on them. Nigg advised to simply remove the beams and ensure the stage had a consistent frequency throughout when they landed. This would allow the performers to accurately perceive the vibrations and allow their muscles to do what they were meant to do in their specific activity. At first, the organization was skeptical but they followed through and the performer’s injuries went away.

I think we can hypothesize that the muscle contractions are the bodies own mechanism in responding to the vibrations. The bottom line is the body adapts to the sensory input it’s given and if we are covering the input of how much force we are receiving then this could be deleterious in overcoming our environment.  This could lead to injury because we might not even be aware of the damage being done. Imagine if you didn’t have any pain receptors in your skin against a hot stove. Not to get all sciency but while you wouldn’t feel the sensation of pain from the stove, it would still impact your body in a negative way without us even knowing. This is why we have pain receptors to tell us that we are in danger.

While these air bubbled shoes are perfectly fine to wear casually, we must understand they were not designed to truly take the demands of many sports no matter how cushiony or flashy they look. There is no correlation to cushion and injury because that’s not the question we should be even asking. Perhaps the question we should be asking is “Are we receiving the right input in this activity and do our feet have enough resilience to adapt and respond to it? Funny how sometimes the best looking shoes aren’t always designed for performance that we are sold on. You wouldn’t want a Ferrari to tow your car even though you might be breaking people’s necks trying to do it. That’s what tow trucks were designed for.  It’s hard in this day in age to focus on keeping things simple since we are always looking for novel stimulus to escape from the simple boring truth. It’s important to critically think for ourselves the next time someone sells us a flashy product telling us it will enhance our life. But before we pick something to wear for our sport or activity, we should consider the novelty of the specific demands of that sport and how they allow us to load our feet and our body. The next question, which I think is a good idea, is to ask ourselves how much of this activity can we do before we feel like we can’t walk for a week.  Consider your own anatomy and how it may be a bit different and run with it. I’ll leave you with this golden quote by Daniel Lieberman, a Harvard professor,  “How one runs probably is more important than what is on one’s feet, but what is on one’s feet may affect how one runs.” Our shoes or maybe lack of them and how we move in them certainly play a role in our movement.

Kick off your shoes with this jam


Also I have to pay homage to my favorite singer of all time Chris Cornell! RIP





Happy Feet?

Nigg, B.M., Liu, W. The effect of the muscle stiffness and damping on simulated impact force peaks during running. Journal of Biomechanics. 1999;32:849–856.

What the Foot by Gary Ward


The Vestibular System And Its Importance

The vestibular system is the forgotten designated driver of our body. It’s always overlooked and doesn’t get enough respect for all that it does. It’s the first sensory system to develop while in the womb and acts as the foundation for the other systems such as your visual and proprioceptive system. When a baby’s vestibular system develops it interacts with gravity and further develops the child’s nervous system for movement. In fact, all your muscles and your eyes are neurologically tied to the vestibular system and it forms the body map and movement maps of how we interact with the world. The coordination of the eyes and head together serves as the basis for all the interactions in our lives.  Your head follows your eyes in almost every activity whether you’re keeping your eye on the ball, taking notes from a board, or even reading across this page. Another big factor the vestibular system contributes to are maintaining balance and equilibrium. The first sign of brain deterioration is when balance starts to fail (Smart Moves,p. 111 Carla Hannaford).  Overall this system is HUGE as it impacts how you process the environment, how you move, your sense of self, and even how you learn! It makes almost every other system possible.

Image result for big deal meme

The inner ear acts like gyroscopes in your head maintaining balance by allowing the tiny hairs and gel like liquid to communicate to your brain that your head is moving. Another good way to think of the vestibular system is modeling it like a neural GPS. The brain is the central processing unit of the GPS and it looks for three satellites which would be the visual system, vestibular system and the movement/sensory (proprioceptive). These satellites relay to the brain where it’s going and how to efficiently get there.

Image result for GPS

New Air Force Satellites Launched To Improve GPS

Without those sensory organs of the vestibular system intact, our sense of balance and what we perceive to be happening in our body can go haywire.  Anyone who ever had or knows someone who had vertigo understands how scary it can be. To them, it feels the world is literally spinning out of control and fainting ensues because of the overwhelming sensations. The brain is not getting the correct or maybe adequate information from their inner ears and eyes and in turn, they don’t feel safe. When you don’t feel safe your arousal level, attention and sympathetic nervous system kick in. This is another example of a high threshold strategy when it’s not needed. Some of these high threshold strategies could be manifested by motion sickness, fear of spinning, claustrophobia, and dizziness. Things are out of balance in the vestibular system.

There are a couple of factors that go into balancing. Just like satellites relaying to the GPS of where it is, the eyes, the inner ear, and the proprioceptive system must work together. Dr. Cobb, the founder of Z-health, states that the vestibular system requires Signal Quality and Signal Integrations. Signal quality is how well the eyes, inner ear, and nerve endings in the joints and muscles coordinate together to provide a signal to the brain referencing what’s going on around you. Signal Integration, on the other hand, is about how your brain processes information its received from the signal quality sources such as the eyes and inner ear. Any small deficit in either the signal quality or signal integration can disturb how you sense, move, and interact with the world. Amazingly half of the children with some kind of learning disabilities have some kind of vestibular dysfunction. Here are some studies exhibiting how the vestibular training improved learning  Study 1, Study 2, Study 3, and Study 4. Just like any movement or reflex, the brain has to receive input and integrate it in order to form an output. The key to challenging balance is to stress both the signal quality and signal integrations. An example would be if you balance on one leg for about ten seconds and then doing it again but this time closing your eyes. It’s harder, isn’t it? Your challenging the signal quality by taking vision away so your inner ear has to work even harder.

It’s easy to overlook the vestibular system and not appreciate all that it fully does. By working on the vestibular system we can impact how we sense and process the world around us and become more resilient. The way we create this resiliency is challenging the inner ear of the vestibular system and integrating it with the other systems. The phrase “Its all in your head” applies definitely now because by simply moving our head is what stimulates the inner ear and the vestibular system to act. The simple activities and movements that we are all aware of such as running, jumping, spinning, rolling, flipping, rocking, and crawling all work the vestibular system without us even realizing because it involves moving our head (Original Strength).

Image result for laughing on the floor

Rolling on the floor laughing will also count. I MEAN HAVE YOU SEEN ANCHORMAN!


These activities allow the fluid in our inner ear to move and signal the brain that we are in motion and hence adapt to whatever position we are in. Also, take into consideration differences in the vestibular system of a kid easily banging out cartwheels one after the other and an adult struggling to balance his hands on the floor to perform one. They are on totally different levels. The kid’s inner ear is much more adaptable and can tolerate the spins and whirls of the adventures of being a kid but for the adult, their vestibular system is a bit deconditioned.

Image result for kid cartwheel

Life is a magical land full of candy and gumdrops.

What I’m sure feels like trying to find the keys in dark with a hangover.

Just like in weight training how the volume and intensity are manipulated, balance training manipulates the signal quality and signal integration. In other words, the visual system, inner ear, movement/sensory system and integration skills must be challenged together. I will reference Dr. Cobb’s formula from his sample page from the vestibular system which is also referenced at the bottom. (Z-health-

Stance/Body Position + Head movement + Eye movement = Increasing Difficulty

The mix and match of any of these three factors and it will contribute to challenging the intensity of your vestibular system. Moving your head and eyes in the cardinal directions similar to a clock is another fantastic way to progress.

The easiest start progression would be lying down and rotating your eyes and head in the same direction. If you really feel like shaking up the way you process the world then the hardest variation would be walking forwards or backward and moving your eyes and head in opposite directions (please do it in a closed environment where people understand the purpose of this exercise or alone so people don’t think your a walking exorcist). Here is a much better explanation by Dr. Cobb putting everything into effect.

Because we like to think like scientists, we can use a Test/Retest to establish a baseline to see if any of the drills work.

Test: Simply balance on one leg for 15-20 seconds and repeat with the other leg.

-take notes of how you felt and what happened either in your head or write it down

Retest: the one leg balancing

Did it feel easier, and or did you last longer? If it felt easier you made a reset in your vestibular system.

Another great way to challenge the vestibular system is to add any type of crawling or rolling variation. Luckily if you have any bear crawls or Get Ups in your program, you’re already working your vestibular system without even knowing. Lucky you! Here are some excellent drills by Tim Anderson teaching you use your eyes to drive your head and learning to crawl


Take time to breathe in each position to really own it and don’t let the simplicity fool you. Your vestibular system is working hard to get into position especially in an elevated half roll.

If you really want to dig deeper I implore you to check out the Near Point Gaze Stabilization and Far Point Gaze Stabilization on Z-Health. These drills are similar in which you keep your eyes fixed on something while moving your head in all the cardinal directions. The only difference is that the former is near your face and the other focused out on a target in the distance.

I’m sure by now you understand that moving your head and rolling is good but you’re probably thinking how is any of this going to make me lift more, be faster, conquer the world? I agree that these drills and skills are not going to automatically transform you into the cream of the crop.

Christopher walken cowbell 1 -  Bruce Dickinson: "The cock of the walk, baby!"

But they do serve as the foundation for all these great actions. If someone is able to process the world around them better, they don’t have to hold their breath, their already more relaxed and more trusting of their body since every little part is up to par. Also, you’ll probably pick up things around you faster than the next guy and won’t have to think about it. When you process things better it becomes easier.  It’s tuning a better software for a champion and taking off the parking break.

Here is some more food for thought, perhaps the reason many people’s vestibular systems are so deconditioned is because we no longer play. Playing stimulates the vestibular system and is why growing up kids were encouraged to play outside on swings, merry-go-round, tumble, crawl and just have fun. You don’t have to teach a kid to play or use their vestibular system. Just let them be as nature takes care of things!


Now let your ears jam out to this awesome song



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Ayres, A. Jean. “Deficits in sensory integration in educationally handicapped children.” Journal of Learning Disabilities 2.3 (1969): 160-168.

Carla Hannaford, Smart Moves(Salt Lake City; Great River Books, 2005,) p. 111

Original Strength: Regaining The Body You were Meant to Have by Tim Anderson and Geoff Neupert


Bilateral positons to teach unilateral positions

I was inspired by this video of Quinn Henoch’s, founder of, YouTube page. I think it displays a concept that is paramount in learning and developing  motor control in unilateral exercise

This was a great way to teach the single leg RDL. Many people dread doing single leg work because they find it difficult get into position let alone balance on one leg. By hip hinging first bilaterally, you learn to shift your COG(Center of Gravity) to each foot and understand how it feels to have more of your weight on that side. By having your weight on each foot, you can take a breath to solidify the position there and learn to own it. A fantastic quote by Gray Cook sums this up “If you can’t breathe in that position then you don’t own it. You can’t survive in that position”. If you’re not able to breathe there then it becomes a high threshold environment because your body perceives it as a threat. By being able to breathe in this position they are able to own it and survive. It also helps for a person to have an understanding that their weight is supported by both of their feet and then can we explore in shifting their weight over each limb to get them more comfortable. Once they’re set in position and own it they can pick up the other leg and extend it. Now we can have fun loading it and plan accordingly with their mobility whether to pull from the floor or a box.

Another fantastic example of applying this approach is Pablo Orozco, Clinical athlete student, and founder, demonstrating the same concept of starting with a bilateral squat and progressing it into a pistol by shifting his weight to his right side and displaying the motor control on one leg.



This is an impressive display of the many planes of motion he can own and the fact that he can get there builds more resiliency. Katy Bowman talks about this concept of owning the different planes of motion in her book “Move Your DNA”  calling it “rainbow loads”. Pablo definitely traced the rainbow like a ninja! Kudos! The fact that your body can get into those different ranges of motion without feeling like you’re holding your breath is not only a remarkable display of motor control but can be a preventative measure from injury.

We can even apply it to the upper body as Karen Smith, SFG chief bodyweight instructor, and Phil Scarito, Master SFG, demonstrate the one arm pushup.

Phil sets the position by setting his whole body and maintaining tension as he corkscrews both of his shoulders into the ground. He uses the power breath to add more tension to the system so he is stable as he moves one arm off the floor and executes the movement. This is also an excellent exercise to teach the one arm one leg pushup which would be the gold standard of this concept which is to teach you to root with one hand and your opposite foot. If you can do that then you’re a stud!

While we do most of our training bilaterally, we cement our success by getting on one foot and spending time in those positions. Being able to shift your weight to each foot or hand is paramount in life and in many functional activities.

How can we develop this strategy? We need to start teaching people to be mindful and aware of their own bodies. Also, we need to slow down the pace of the movement so they can actually feel and breathe in those positions. So for instance, if we are in half kneeling or tall kneeling, we learn to own that position by getting there and breathing there in that position. I’m not saying that breathing is the answer to all your life’s problems but it is a start as you get the brain to say “It’s ok to be here, there is no threat, so now let’s move”

If you think this gave you something to think about, helped made you look at things in a different way, or liked it please share it.


Want to enjoy some riffs? Give Eric Gales “The Liar”a listen to!


Have a great Day!

DNS Core Activation

DNS Core Activation

For those who are obsessed with how to brace and use the core, I think this is an excellent video   Core Activation by Hans Lindgren to teach us to brace 360 degrees

It starts with the diaphragm as it pushes down to get intraabdominal pressure. A way of ensuring the right diaphragm pattern is to see the lower ribs expanding horizontally(0:32). I can’t remember if it was Chris Duffin or Bill Hartman who said that when you breathe you want to inhale horizontally and exhale vertically. When people classically breath up in their chest and clavicle this would be an example of what we do not want to see. This is inhaling vertically and all the secondary respiratory muscles turn on. Hans makes a good point on the people who breathe up in their chest that as they do so their stomach goes in and this overloads the muscles above their chest and then people wonder why their traps are so stiff. The student lays down on their back so he’s in a stable position supported by the floor/table and here we can observe the horizontal expansion of the ribcage. Now the connecting point is that we want the diaphragm moving the breath down to the abdominal cavity. He puts his hands on the ASIS (anterior superior iliac spine) asking the student to breath into his fingers to ensure the breath is complete as it moves down. Once the pattern is set the student has exhibited that he can create that pressure from the front and back and the next step is to automatize the pressure. The key is to maintain that pressure as he breathes out and never lose it. The ability to maintain this complete pressure exemplifies being able to consciously brace and we can apply this when we are under a load when lifting.

Chris Duffin has learned from DNS model and his thoughts are similar when he tells people to “Inflate the Obliques” (3:15) as this cue is a side effect of 360 degrees of bracing of his entire torso.

Back to the original video as Hans uses the thera-band as tactile feedback to teach the student to truly use his diaphragm to expand his ribs 360 degrees (2:42). Similarly, the purpose of a lifting belt is another example of tactile feedback to teach the lifter to force their torso to brace 360 degrees.The next position (3:30) is similar as he did on the table getting the person to take a breath at the bottom and focusing on maintaining that pressure and push against it.

At (3:58) we have the dead bug series still focusing on the fundamental key to holding and maintaining that pressure. Hans has the student maintain the position, building upon maintaining the pressure all the way down, as he moves his arms and legs. Another thing I want to point I think is fantastic because people forget to look for this in all their “Functional training” is Hans is teaching him to maintain the pressure in all planes. At (4:30) he pushes on his arms and legs also on the same side as if trying to flip him over to his side and hold the brace in the transverse plane and frontal plane. These are often the forgotten planes and are tough because we are not used to training in these positions(4:46). Also to continue the training, Hans has him resist him in the anti-extension of both the student’s arms and legs and even throwing in the resisted contralateral pattern that we see normally in the deadbug (5:07). These are all spices in the deadbug dish but Hans states that we must never lose focus of drill of the deadbug which is to have awareness of the position of the abdominal cavity and the chest position that is dictated by the ribs in bracing. The breath and pressure of the brace must be always maintained no matter what our limbs are doing.

At (5:20) Hans displays the wall supported DNS deadbug as a further progression as a way to integrate more parts to the complexity. This involves such getting the student’s lats turned on as his hands push into the wall. Again he notes to never lose the brace and points to his obliques (5:51) to make sure that he is not losing the brace and just not to mistake that you’re doing it right because your abs are on.

I feel the whole point is to automize this brace until it becomes a reflex as if someone was going to perturb your movement. I know this is something I definitely explore more and encourage you to explore it on your own or with someone.

Cheers and give Jeff Healy “Which One a listen. It’s awesome sauce!