A New Approach to Equalisation: What I learnt from my MRI Experiments

A New Approach to Equalisation: What I learnt from my MRI Experiments

Hey Freediving Family!

For those who usually watch my Vlog this will be a very different kind of video. In this video I will be presenting some new ideas on equalisation and exploring what I believe could be some misconceptions in our equalisation knowledge.

As a lot of you already know I recently did a bunch of equalisation experiments inside an MRI machine that was capable of creating MRI videos. For the first time we were able to see what was really moving and how it was moving when we equalise.

When I did the experiments I honestly didn’t think I would learn anything new but after studying the videos I realised that some of our knowledge wasn’t aligning to what I was seeing in the MRI.

Before I begin I would like to put up some disclaimers:

1: The information I’m going to present was new for me and those in my freediving circles, I haven’t presented these ideas to anyone so far that doesn’t consider the knowledge or techniques to be new but that doesn’t mean that freedivers out there haven’t been doing this for years, or haven’t known about this for years. I have some pretty educated and skilled freedivers in my circles but by no means can I speak for the entire freediving community.  

2: I’m aware that the information i’m presenting was based on the MRI videos from one person, me. My equalisation technique may be imperfect, it may be unique to me and my anatomy. I would like us to think of this information as preliminary findings and in truth the only reason I’m presenting these ideas publicly now is because the overwhelming success I have been experiencing teaching these new equalisation techniques to my students.

So far I have taught these techniques to 60 students and like I said the results have been incredible. Students learning mouthfill equalisation, Frenzel equalisation and feet first divers learning how to dive head first in short periods of time. But 60 students is a rather small amount for a case study and so I want to open this up to the freediving community so that you can try it or try it with your students, friends, training buddies so that these techniques can be tested and developed further by all of us.

3: The final disclaimer is that I typically teach 8 day training camps. Because I teach in those time frames means that I will naturally develop methods and techniques that can be taught effectively in that time frame but the methods may not be applicable to all situations.

A huge thank you to Michael Board, Goran Colak, Matt Malina, Alexey Molchanov and Dean Chaouche. Conversations that I’ve had with these divers have helped me form the ideas that I’m presenting today and a huge thank you to my Patrons on Patreon.

Patreon is where I’m creating an extensive video manual for Freediving. It’s $5 a month to get access and the funds help me carry out research like this. I hope that all my Patrons feel a sense of ownership of the discoveries made here. You literally funded this research so thank you as always.

Okay let’s begin.


Title: The Larynx

I want to start by drawling attention to this area here. *** This group of muscles, cartilage and tendon Is the Larynx. It ranges from the epiglottis up here to the sub glottis right below our vocal cords. The larynx plays probably the largest role in freediving equalisation but it’s role so far has been underplayed.

Let’s look at the larynx’s range of movement. We’re able to lift it up *** and we’re able to pull it right down *** There’s quite a large range of movement. The real interesting thing about the larynx is that it has paired movements with so many of the muscles and movements in our respiratory system. Watch here *** this is a video of me just breathing in and out of my nose and watch how to larynx moves gently up and down. So when I’m activating my respiratory muscles my larynx is moving along with them and i’m not even aware of it. Paired movements with the larynx is an important factor to keep in mind going forward.

In this video I’ll present first when I think could be misconceptions about a specific technique and then suggest an alternative method. So with our attention placed on the larynx let’s look at Frenzel equalisation. We are going to look at the equalisation itself and reverse packing.


Title: Looking at Frenzel

After studying the MRI videos it seems to me that the tongue does not play the role I was expecting in Frenzel equalisation, by which I mean it doesn’t really play a role in the creation of pressure itself. This was a surprise to me because in every single Frenzel presentation i’ve ever heard and personally taught, emphasis was placed on developing control of the tongue.

This is a video of a T Frenzel. Which I suppose is the most classic style of Frenzel that is taught. *** pay attention to the movement of the larynx. This is a video of a K Frenzel *** once again pay attention to the movement of the larynx. Here’s a H Frenzel *** You can see quite easily how the driving force for the equalisation is the Larynx and not the tongue.

So why does it seem to us or feel like it’s the tongue that is moving? I recently threw around some ideas with a speech pathologist and she confirmed that the tongue will contract or tense up during the movement of a Frenzel equalisation but not in a way contributes to creating pressure and pushing air into the middle ear. We have much more awareness of the tongue than we do of the larynx so we are much more aware of it tensing than we are of the larynx lifting.

After looking at all this it seems very obvious to be that the tongue’s role in Frenzel equalisation is very simply too create a seal so that air does not escape the mouth while the larynx lifts upward to push the air into our nasal cavity.

Just to demonstrate this further here is a video of a P Frenzel. Where I create the seal with my lips, and don’t involve my tongue at all. *** My lips are the seal and then I simply lift my larynx.

This has all made me rethink my approach to teaching Frenzel. I believe larynx control is paramount and from now on when I introduce Frenzel equalisation to a diver I don’t think I will spend significant time focused of the positions of the tongue, as long as my students can place their tongue and mouth in a comfortable position I think the time will be better spent focusing on the larynx.

Now I’m not saying that developing tongue control and mastery of the different tongue positions, P T K H isn’t important. But I’m starting to view it as more of a precursor to mouthfill equalisation as opposed to being an integral part of Frenzel. Because as long as the nostrils are pinched, the soft palate is open, and the tongue or lips are creating some kind of seal then all you have to do is lift the larynx and you will frenzel equalise.

Let’s look at reverse packing now. Reverse packing is how we refiill our mouths with air from our lungs so we can keep Frenzel equalising. It’s an essential part of the standard frenzel technique Here’s a video of me doing a medium sized reverse pack. *** here’s a video of me doing a small reverse pack, which is much more like the reverse pack that we would do while actually diving.***

You can see here the mechanics of reverse packing. The larynx drops down and then the vocal fold opens and as it opens the larynx drops down a tiny bit more creating suction, which sucks the air from our lungs into our mouth. Reverse packing happens quite quickly and this MRI could only shoot at 5 frames per second so the video gets a little jumbled.

So in order to reverse pack we need to be able to drop the larynx. In order to Frenzel we need to be able to lift the larynx. This is why I believe it’s important to teach beginners who are learning Frenzel to develop larynx control from the absolute beginning. As those divers progress onward we need them to be able to isolate the larynx, to move it freely and independent of the muscles around it, the soft palate, the tongue, the respiratory muscles.


Title: Frenzel: An Alternative Method

The technique that I’m going to suggest for Frenzel isn’t that different from the one we’re currently working with…but the emphasis is very different. The focus is on the larynx and not on the tongue. But in short it goes like this.

1: Develop control of the glottis
2: Develop awareness of the soft palate
3: Develop control of the larynx, learn how to lift and lower it
4: Choose a natural position to seal the mouth, P T K or H
5: Then pinch the nostrils and put it all together.

Before we move on let’s quickly look at how to teach someone to develop an active control of their larynx. For the most part we only use our larynx in conjunction with speaking, breathing and eating and so most people won’t have full control of it initially.

To do this we do what are called queuing exercises. A big thanks to Dave Mullins, the Australian Dave, not the deep diving kiwi Dave, for fleshing out my understanding on the concept of Queing. It is basically where we tell someone to do something with their body that they know how to do which causes them to indirectly move their muscles in the way that we want for our specific exercise.

For example to get someone to lift their larynx I often ask a diver to simply stick their tongue out as far as it will go. Now some people when they do this will lift their larynx as well. Some people don’t. It really depends on whether that person has paired movements between their tongue and their larynx in that way.

The next queuing that I use will be to get divers to stick their tongue out as far as it will go and then I ask them to heave as if they were vomiting. This has a 100% success rate in terms of getting students to lift their larynx. I don’t actually think this is the best queuing exercise, there must be something simpler but it just works so I keep doing it. If you do know of any others I’d love to know!

When I first began teaching freediving and I was teaching a diver to Frenzel I would ask them to simply pinch their nostrils put their tongue in a T position and then make a T sound. It worked some of the time but for the most part it didn’t and looking back now I realise that it worked only with divers that had a paired movement between their larynx and their tongue so that when they were building up pressure to make the T sound they were naturally lifting their larynx.

To teach someone to lower their larynx or to be aware of lowering their larynx is actually quite easy. You simply ask them to stick their tongue out as far as it will go and then to fold the tip of the tongue over itself. As we push the tongue inside our mouths like this we all naturally make space for it by lowering the larynx. For me there is also a 100% success rate with this exercise.

So just to reiterate the simple steps to teach someone Frenzel:

1: Develop control of the glottis
2: Develop awareness of the soft palate
3: Develop control of the larynx, learn how to lift and lower it
4: Choose a natural position to seal the mouth, P T K or H
5: Then pinch the nostrils and put it all together.

Once a student has a basic ability to move the larynx I think it’s a good idea to give them larynx control exercises and just to give you an idea of where my head is at with that here’s an example.

  • 5 x full larynx movements, up and down with the tongue neutral
  • 5 x full larynx movements with the tongue in a T position
  • 5 with the tongue in a P position
  • 5 with the tongue stuck out
  • 5 with the tongue folded over itself
  • and repeat this series 5 times.


Title: Looking at Feet First Equalisation

So let’s look at a method of getting a diver who is only able to equalise feet first to be able to equalise head first.

To my knowledge there are two main issues that can stop a diver equalising head first. The first is an anatomical issue which is they have tight, short or in generally tricky eustachian tubes. This problem can be solved with relative ease but it’s not this particular issue that I believe I’ve developed a new solution for.

It’s the second one, which is when the soft palate closes against the back of the throat or mouth and does not allow air to pass into the nasal cavity. The solution is very simple but I do just want to say that I believe simply teaching divers to Frenzel equalise in these cases will almost never solve this issue.


Title: Feet First Equalisation: An Alternative Method

So have a look here at what happens to my soft palate when I drop my larynx *** it opens right up. As I lower the larynx my soft palate opens or is pulled open. So far in my experimentation this is universal. When a feet first diver lowers their larynx their soft palate opens too.

So what I am now getting feet first divers to do is to do a normal Frenzel equalisation but with an extra step. Before they lift their larynx to equalise they drop their larynx down first. They drop it down to open up the soft palate and then lift it to equalise. I call it the Drop Frenzel…because all these little things need cool names.

It’s a very simple thing and so far for me the success rate has been higher than I have observed with any other technique or approach. But this will only work if a diver has a reasonable control of their larynx. Without that control they will struggle to coordinate the movement.

For me this feels like another reason why it’s a good idea to introduce larynx control from the beginning.

I have had the best results with this method by simply having the feet first divers dive feet first for 1 or 2 days and work on their standard Frenzel technique. Then on day 3 I get them to work with the Drop Frenzel. Now with the divers I have trialled this technique with so far by the 4th or 5th day of diving they haven’t needed the Drop Frenzel. I assume they have developed enough control of their oral muscles in that time to equalise while keeping their soft palate open. Or perhaps doing the Drop Frenzel is just a great way to develop control and awareness of the soft palate. It’s definitely too early to say.  


Title: Looking At Mouthfill Equalisation

Okay so let’s look at mouthfill equalisation. I’m going to start by showing you a video of me charging a mouthfill. In this video I’m charging air into my nasal and oral cavity at the same time. *** I want to show you this video so you can see how much air sits in the throat on top of the vocal fold and to see the position of the mouth at the start of a mouth fill.

Now this is me doing a constant pressure mouth fill *** A constant pressure mouth fill is simply when we apply pressure all the time for a constant equalisation. Our ears are equalised all the time as we descend. Now since studying the MRI videos and since I’ve been experimenting with other mouth fill techniques I feel like the constant pressure mouth fill technique is inferior to other techniques…or at least that it is not a good approach to teach to divers who are beginner with mouth fill equalisation.

Once I saw just how much air sits in the throat on top of the vocal fold I started thinking about the amount of divers who are complaining about leaking mouth fills and swallowing their mouth fill. It seemed to me that maintaining enough pressure for a constant equalisation was excessive for the vocal fold or the glottis or whatever we want to call it. If we are creating enough pressure to equalise we are creating pressure against the vocal fold. The only divers that I believe benefit from a constant pressure equalisation are divers who have strong no hands equalisation. Divers capable of holding their eustachian tubes open so that they barely have to push to cause an equalisation.

The other main thing about the constant pressure mouthfill that stood out to me when I was studying the MRI was the tongue roll. So in the explanations of the constant pressure mouthfill that I have heard and taught myself after the air has compressed to the point where we can’t maintain pressure with the cheeks we put the air behind our tongue in a T position and then slowly roll the tongue back to a K position and then a H position.

But this is a video of a T Frenzel *** note the position of my tongue. There’s air above my tongue. This is a K Frenzel *** note the position of my tongue. Almost the entire surface of my mouth is making contact with the roof of my mouth.

I’m really not certain that the tongue has the ability or the coordination to roll back in such a way to maintain constant pressure. This makes perfect sense to me because the moment where most of my students are losing their mouthfill is in the transition from the T to the K position. And it seems here like moving from the T to the K would slam the tongue against the roof of the mouth, creating too much pressure causing a diver to lose the mouthfill.

Have a look at this video. This is me transitioning from the P to the T then the K and H positions. *** it just doesn’t seem to me like the tongue can move seamlessly from one to the other. So then…what are all those incredible divers out there who are executing constant pressure mouth fills doing?

This is mostly speculation because I really haven’t tested this idea enough. I have tested it on only 3 100m+ divers now that use a constant pressure mouth fill. But all of those divers when they transition to the tongue begin to engage the larynx in a constant slow lift. So most of the pressure for the equalisation is being created by lifting the larynx. I asked them what they were doing with their tongue and they all described sliding their tongues back, not rolling them back.


Title: Mouthfill Equalisation: An Alternative Technique

So let’s have a look at the mouthfill technique that I have been working with since the MRI scans. The success of this method is really what inspired this whole video because I have been so blown away by how easily students are learning and executing it.

1: A diver charges air into both their nasal and oral cavity at the same time, making sure they lower their larynx as they charge.

2: They focus on keeping their larynx lowered, not lifting it at all and creating no pressure with it. It stay down.

3: The divers equalise by simply pushing with their cheeks then relaxing between equalisations, not maintaining constant pressure and while they equalise with their cheeks the whole time they keep their larynx held down.

4: When the air is compressed to the point where they can’t push with their cheeks they move the air back and forward from their cheeks first to a P Frenzel, then back to their cheeks and eventually to a T K and H Frenzel. When they’re frenzeling they are creating pressure with their larynx and not their tongue.

I call it the single source mouthfill because at any time you are only creating the pressure to equalise from one source, from one muscle group. Also because all these things need cool names!

So let me talk about why I believe the Single Source mouthfill has been so effective. For starters by keeping the larynx dropped for the first half of the mouthfill we have ensured that the soft palate is kept in an open position. Soft palates getting stuck is a very common mouthfill issue. Though since I started teaching this method I haven’t had a single student mention that their soft palate suddenly got stuck or that they suddenly were not able to equalise. Keeping the larynx lowered ensures that the soft palate stays open. *** just as a reminder lets look at this video.

It also ensures the tongue is pulled down. One of the most common issues divers run into when they learn mouthfill is they push their tongue up against the roof of their mouth. They put their tongue into a Frenzel position. Which I think is incredibly understandable. It’s the position they have put their tongue in for their whole diving lives. It’s comfortable, it’s what they know. But then with the tongue against the roof of your mouth you can’t push the air that’s in your cheeks back behind the tongue and into the nasal cavity.

I believe that one of the most common reasons that divers lose their mouthfills is because they equalise with too much pressure. The vocal fold or glottis is always the weakest point and so if we equalise with too much pressure we will lose the air back into our lungs. I’ve spent a disproportionate amount of time over the past few months starting at people while they execute dry mouthfills. Every single diver I observed used their larynx in conjunction with their cheeks or their tongue, depending on the type of mouthfill they were doing, while they were equalising.

So it’s become my suspicion that when divers are learning mouthfill they are doing the same thing. Pressing with the cheeks and the larynx at the same time. It would be very natural to do so because they would simply be using their larynx like they are accustomed from their Frenzeling habits. I do think though that equalising from both these areas at once is too much for a beginner or intermediate mouthfiller and it’s easy to over-pressurise and then lose the mouthfill. Experienced divers obviously have worked out the exact pressure required but this takes time.

Now by focusing on keeping the larynx pulled down and only using the cheeks to create pressure the divers learning this form of mouthfill equalisation so far didn’t find themselves leaking their mouthfill or swallowing their mouthfills. I believe it is because they are not equalising with too much pressure.  

I believe the Single Source mouthfill offers more control and eliminates many issues that divers who are learning mouthfill are running into. We keep the larynx lowered, this keeps our soft palate open, it keeps our tongue down and out of the way and we equalise from only one source. When I’ve been thinking about all this I keep coming back to how natural it is for divers to revert to Frenzel habits, to push their tongue up against their mouth, to push with their larynx. And in my experience teaching mouthfill this would happen all the time.

So let’s look at the second half of the Single Source Mouthfill. Throwing the air back and forth. So be honest when I first taught this I really wasn’t sure if it would work with divers just learning how to mouthfill. I thought it would be too complex and they wouldn’t be able to coordinate it. But I was wrong. Like I said in the beginning. The only reason i’m making this video with ‘preliminary findings’ is because of the overwhelming success of the techniques.

My reasoning for throwing the air back and forward, frenzel equalising and then storing it in the cheeks. *** Remember how much air sit in the throat against the vocal fold. Any air sitting on top of the vocal fold is at a risk of being leaked or swallowed. I’ve been making sure when I have been teaching this that the divers are not Frenzel equalising with the typical strength of a Frenzel but doing it more softly and I’ve also had them working a lot with tongue drills moving through the sequence, P T K H.

And that’s the Single Source Mouthfill. I think it’s quite simple and controlled and it’s definitely incredibly easy to learn! We will have to see in the long run if it is as effective a technique as other mouthfills for greater depths but I for beginners I really do believe it is unparalleled.

So to summarise:

I believe that when we are learning or teaching equalisation we need to place emphasis on learning larynx control. We need to be able to isolate it lift it and lower it, with the tongue in many positions. We need to be able to move it up and down in smooth, constant motions.

For Frenzel.

1: Control the vocal fold
2: Control the soft palate
3: Create a seal with the tongue
4: Raise the larynx
5: Lower the larynx to reverse pack more air into the mouth and repeat.

For Mouthfill:

1: Charge the mouthfill into the nasal and oral cavity
2: Keep the larynx lowered and pump with the cheeks.
3: Throw the air back and forward from the cheeks to behind the tongue into a Frenzel.

It’s all very simple when I say it like that!

I’m now going to re-film all my equalisation videos on Patreon. I’ll systematise this process so it’s a smooth transition learning Frenzel, Advanced Frenzel and the Single Source Mouthfill. They’ll easily roll onto eachother.

I would really love to know your thoughts on this! I’d love your feedback! I’d really love to see these techniques being trialled and developed by the community. I’m looking forward to seeing where others take these techniques.

Thank you once again to my Patrons on Patreon. They are the ones that make these videos possible. If you want to join you can donate whatever you’re comfortable with. 2 dollars a month, 5 dollars, 10 dollars, whatever you’re comfortable with.

Thank you once again and I’ll see you in the water somewhere!

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