Frenzel Technique: How to Equalize for Freediving

Frenzel is a piston. You trap a small pocket of air in your mouth and upper throat, seal both ends of that pocket, and use the back of your tongue to squeeze it. The squeezed air has only one place to go: up through the Eustachian tubes into the middle ear. That is the entire maneuver. It has nothing to do with your lungs, which is exactly why it keeps working when Valsalva quits.

The contrast matters for one reason. Valsalva raises pressure from below by pushing with the chest, so it dies as the lungs compress on descent. Frenzel raises pressure from a closed pocket above the glottis, independent of lung volume. This page does not re-explain Valsalva. If you want the full comparison of methods, read the equalization techniques overview first, then come back here to actually build the movement.

The reason people struggle is not strength. It is isolation. You already own every muscle you need, but you have never fired them independently on purpose. Once you can separate the tongue movement from a chest push, Frenzel becomes automatic. This is the technique that removes the depth ceiling most beginners hit around 10-15m, so it is worth the practice time it demands, alongside solid breathing technique before the dive.

Frenzel is really three separate skills stacked on top of each other. Learn each one on its own before trying to combine them, because a fault in any single group kills the whole equalization.

1. The glottis

The glottis is the valve at your voice box. It is what you close when you hold your breath, grunt, or brace to lift something heavy. In Frenzel it seals the bottom of the air pocket so your squeeze cannot escape down toward the lungs. To find it: start to exhale, then stop the air dead without using your lips. That hard stop in the throat is the glottis closing. Hold that closure and try to make a 'guh' sound. If no air comes out, your glottis is locked.

2. The soft palate

The soft palate is the flexible tissue at the back of the roof of your mouth. It has three positions: neutral, raised (routing air out the mouth), and lowered (routing air out the nose). For Frenzel you want it in the neutral middle position so air can travel from your mouth into the nasal passage and up to the Eustachian tubes. If your soft palate is stuck up or down, the air pocket is cut off from your ears no matter how well the tongue works. Alternate humming (nose) and blowing (mouth) to feel it move.

3. The tongue

The tongue is the piston. Specifically the back third of the tongue rises and drives up and back against the roof of the mouth, compressing the sealed pocket. Most people move only the front of the tongue at first and get nothing. The motion you want is closer to the back-of-tongue lift you use for a hard 'K'. When all three groups cooperate, that single tongue stroke fires air into both ears at once.

Do this on dry land, sitting up, with clear sinuses. A cheap nose clip helps because it frees your hands, but pinching with your fingers is fine to start. Never rush this into the water before it is reliable dry.

1. 01 —Pinch your nose completely closed so no air can leak out the nostrils.
2. 02 —Take a normal breath and hold a small amount of air in your mouth, cheeks slightly firm.
3. 03 —Close your glottis: stop any airflow toward your lungs, as if bracing to grunt.
4. 04 —Keep the soft palate neutral so the mouth and nose stay connected.
5. 05 —Lift the back of your tongue and drive it up and back, like the first instant of saying 'K'.
6. 06 —Feel or hear the click in both ears as the pocket compresses and the tubes open.
7. 07 —Release the tongue, reset, and repeat slowly. Aim for one clean equalization every couple of seconds.

Watch your chest and stomach in a mirror while you do this. They must stay perfectly still. Any movement there means you are pushing from the lungs, which is Valsalva wearing a Frenzel costume. The goal is a completely quiet torso with all the action happening at the tongue and throat.

Sounds are the fastest shortcut into the right tongue and throat positions because you already make these shapes every day without thinking. Say each one slowly and freeze on the part that matters.

The K sound

The back of your tongue rises to the soft palate to make a hard 'K' or 'guh'. Freeze at the contact point. That is almost exactly the Frenzel piston position. Say 'K, K, K' with your nose pinched and you will start pushing air toward your ears.

The T sound

'T' places the front of the tongue against the ridge behind your upper teeth. Use it to build the front seal so air is pushed backward rather than forward out of the mouth. Some divers combine a soft front seal with the back-of-tongue lift for a stronger stroke.

The goodbye or guh sound

Saying 'guh' or the first syllable of 'goodbye' with the glottis closed traps the air and drives it up. If you can make the shape of 'guh' but no sound escapes, your glottis is sealed correctly and the tongue is doing the work.

Try this sequence: pinch your nose, say a silent 'K', and notice where the tongue lands. Then hold that exact position and press a little harder. That press is the Frenzel. If you feel it work, you have found the movement and the rest is repetition. The mouthfill technique for deep diving uses this same tongue action, so time spent here pays off later.

A correct Frenzel gives you clear feedback. You feel or hear a distinct click or fullness in both ears, the sound is crisp rather than strained, and your chest stays completely still. You can fire several in a row without taking a breath, because you are not spending lung air. If any of that is missing, one of the three muscle groups is failing, and the table below covers the usual culprits.

The single most common trap is mixing Frenzel and Valsalva without noticing. It feels like it is working on land because your strong chest push masks a weak tongue stroke. Then at 12m the lungs compress, the push disappears, and equalization stops. The mirror test is the cure: if the torso moves, it is not pure Frenzel yet. Understanding how deep the technique needs to carry you helps set the goal, covered in how deep you can freedive.

Once a pinched Frenzel is automatic, there are two directions to grow. Neither is needed for recreational depths, but both come up as you push deeper.

Hands-free Frenzel

Hands-free Frenzel replaces the finger pinch with soft palate and throat control that seals the nasal passage on its own. It frees a hand for the line and streamlines the head position, but it demands months of soft palate practice on top of a solid pinched Frenzel. Build the pinched version to full reliability first. Trying to skip to hands-free before that is the fastest way to build sloppy habits.

Mouthfill

Past roughly 30m, even Frenzel runs out of air to work with because the chest has compressed so far. The mouthfill technique solves this by storing a mouthful of air at a shallower depth, sealing the glottis to hold it, and Frenzeling from that reserve on the way down. It is an advanced skill and it is built directly on the tongue action you are learning here, which is why a clean Frenzel comes first.

1. 01 —Master the pinched Frenzel dry until it is effortless and click-consistent.
2. 02 —Confirm your chest stays still on every repetition using a mirror.
3. 03 —Take it into shallow water and equalize early, every 1 to 2 meters.
4. 04 —Only then add soft palate work toward hands-free, or mouthfill for depth.

If you are still early in the sport, ground this in the basics of technique and safety in how to freedive, and remember that no equalization drill replaces training with a qualified instructor from AIDA, Molchanovs, or PADI. Frenzel is a dry skill you can practice at your desk, so put in the daily minutes and it will be waiting for you at depth.