Why your equalization fails in freediving (and it’s not what you think)

Here’s something almost no one tells you when you start freediving: you already know how to equalize. You’ve been doing it your whole life. When a plane takes off and you feel pressure in your ears, you do something — swallow, yawn, blow with your nose pinched — and your ears clear. You didn’t learn this in a course. Your body just knows.

The problem isn’t that you don’t know how to equalize. The problem is that the technique you use naturally may doesn’t work in the position freediving puts you in.

That changes everything.

How we equalize instinctively

Every person has an instinctive way of clearing pressure from their ears. Some people use Valsalva maneuver: pinch the nose and blow, generating pressure on the lungs and sending air to the nasocavity that opens the Eustachian tube. Some naturally use Frenzel without knowing it — using the tongue as a piston rather than diaphragm pressure. A few equalize entirely passively, without even needing to pinch their nose: this is called hands-free equalization, and it belongs to people with particularly favorable Eustachian tube anatomy and mobility.

On land, on a plane, in a pool lying face-up: all these techniques work. The body finds its way and the ears clear. No problem.

The problem appears when you go head-down and start to descend.

Why Valsalva fails in freediving: a physics problem

Freediving is practiced head-first. You descend towards the bottom with your head leading. And that’s where Valsalva — which has worked for you your whole life — starts to fail. Not because you’re doing anything wrong, but because the physics no longer works in its favour.

Valsalva works by pushing air upward from the lungs toward the throat and nasopharynx to reach the Eustachian tube. In an upright position with your head above your body (like on a plane, or floating face-up in a pool), that air travels upward naturally with the pressure you generate. But when you’re head-down, that same air has to fight gravity to travel from your chest up to your ears. At shallow depths it can still work. As the lungs compress and there’s less air available, gravity wins.

The result is familiar to most freedivers who use Valsalva: they always get stuck at the same depth. Ears stop equalizing. Dive ends there. Not because their ears are difficult. Not because they need more practice. But because they’re using a tool that, in that position, simply doesn’t have physics on its side.

Frenzel: the technique that works head-down

Frenzel uses a completely different mechanism. Instead of depending on chest pressure, it uses the back of the tongue as an independent piston: with lips sealed, glottis closed and nose pinched, the tongue moves back and upward as if pronouncing the letter “K” or “G.” That movement compresses the small volume of air in the mouth and nasopharynx, generating enough pressure to open the Eustachian tube.

The fundamental difference from Valsalva is that Frenzel does not depend on lung volume or body position. It works the same head first or feet first. It works with full lungs or with lungs compressed at 25 metres. 

And here’s the key: some people already use Frenzel instinctively without knowing it. If you’re someone who equalizes with their mouth closed, without needing to blow hard, it’s very possible you’re already using Frenzel or something very close to it. The problem is you don’t know it, you don’t consciously control it, and you can’t refine it or take it further.

Mouthfill: when Frenzel needs a reserve

At serious depths — typically beyond 40, depending on the person and its lung volume— even Frenzel eventually needs an air reservoir to draw from. That’s where Mouthfill comes in.

The idea is simple: at a specific point in the descent, before compression becomes too great, the freediver actively fills the mouth and nasopharynx with air and seals it. That oral cavity reserve becomes the “tank” from which all subsequent equalizations are drawn, without needing the lungs at all.

Mouthfill isn’t a separate technique from Frenzel — it’s an extension of it. To learn Mouthfill you need to have Frenzel fully automated. And for most recreational freedivers who don’t exceed 40 metres, well-trained Frenzel is more than enough.

How do you know which technique you’re using?

• This is exactly the question my work as a SHARE Equalization instructor starts from. Before changing anything, you need to understand what’s happening: which technique you use naturally, where in the dive it fails, and why.Some signals to help orient yourself:
  • You probably use Valsalva if: you need to blow with some force, there’s a point where it “feels harder” to equalize at a certain shallow depth with head first, but it comes easier feet first. 
  • You probably use Frenzel (or something close) if: you can equalize with your lips closed, without needing much air, and the movement feels more like tongue than belly.
  • You might be hands-free if: you equalize almost automatically without pinching your nose, with barely any perceived effort, especially in the first few metres.

  In many cases the answer isn’t so clear — some people mix techniques depending on depth, or think they’re doing one thing and are actually doing another. That’s also useful information, and exactly the kind of diagnosis I do in the check EQ calls.

Why I trained as a SHARE Equalization instructor

I’ve been teaching freediving for years.  Equalization has been, by far, the most common ceiling for my students. Not lung capacity. Not relaxation. Not static apnea. But Equalization.

The problem is that for a long time the approach was: “relax, it’ll improve.” And sometimes it does improve on its own. But often it doesn’t, because the problem isn’t one of relaxation but of technique — and without understanding which technique someone is using and why it isn’t working, practicing more is practicing wrong.

SHARE Equalization, the system developed by Federico Mana in Moving Limits, gave me the technical framework to understand equalization from the inside: EQ anatomy, the mechanics of each technique, how to identify what each person does instinctively and how to help them refine it or transition to Frenzel when Valsalva is holding them back and how to learn advanced frenzel (mouthfill). 

I got certified because I wanted to help properly. Not with guesswork, but with a real method.

Free 30-minute diagnosis call: find out exactly where you are

Before working together, I want to understand your situation. A 30-minute call where you tell me how you equalize, where you’re getting blocked, how long you’ve been training and what you’ve tried. By the end of that call I tell you honestly what I think is happening and how I can help.

You don’t need to have tried anything first. You don’t need to already know whether you use Valsalva or Frenzel. The call is precisely to figure that out.

Free. No commitment.