Valsalva vs Frenzel: Why Freedivers Switch Techniques

Valsalva and Frenzel both push air into your middle ear to match the water pressure outside, but they use different engines. Valsalva pressurises your whole chest with your breathing muscles, the way you would blow your nose with your nostrils pinched. Frenzel seals the lungs off at the throat and uses the tongue to compress a small pocket of air in the mouth and nose. Freedivers switch to Frenzel because Valsalva tends to fail head-down and as the lungs compress, while Frenzel keeps working with far less effort.

If you learned to clear your ears on a plane or on a scuba course, you almost certainly use Valsalva. Nothing wrong with that at the surface. It just isn’t built for a head-first descent on one breath.

How the Valsalva manoeuvre works

The manoeuvre takes its name from Antonio Maria Valsalva, an Italian anatomist who described it around the start of the 1700s in his work on the ear. You pinch your nose, keep your mouth shut and push as if breathing out. Your diaphragm, abdominal muscles and chest wall squeeze the lungs, and with the glottis open, that pressure spreads through your whole airway, including the back of the nose, until it forces the Eustachian tubes open.

It is instinctive. Most people do some version of it on a descending flight into Mumbai without thinking. That instinct is exactly what makes it so hard to unlearn.

How the Frenzel technique works

In Frenzel you close the glottis, the gap between the vocal cords, so the lungs drop out of the picture. The soft palate stays open to the nose, and the back of the tongue lifts like a piston against the roof of the mouth. That small movement compresses the air in your mouth, throat and nose enough to open the tubes. Our step-by-step guide to the Frenzel technique walks through each part.

Valsalva vs Frenzel side by side

	Valsalva	Frenzel
What does the pushing	Diaphragm, abdominals, chest wall	Tongue and throat muscles
Air involved	The whole lungful	A small pocket in mouth and nose
Glottis	Open	Closed
Head-down	Often weak or fails	Works much as it does upright
Effort	High, uses large muscles	Low
Effect on the chest	Raises pressure inside the chest	Chest stays relaxed
Typical limit	Often struggles somewhere in the first 10 to 20 m	Works until the lungs are too compressed to refill the mouth
Learning	Instinctive	Needs deliberate practice

The depth figures are rough. Some people Valsalva comfortably deeper; some can’t get past 4 metres. Your own tubes decide.

Why Valsalva stops working head-down and at depth

Upside down, the push gets clumsy

Most divers find that a Valsalva that works sitting upright gets weaker, or fails completely, once they are inverted. The usual explanation is that the air in your chest collects towards your feet when you are head-down, so you are forcing it the wrong way to reach your ears. Whatever the exact mechanics, the practical result is the same: the technique gives out right as you start a head-first descent.

The lungs are already being squeezed

By 10 metres your lungs hold half the volume they had at the surface, and by 30 metres about a quarter. Valsalva works by squeezing the lungs harder, but the water is already doing that. The diaphragm is pushed up into the chest and the chest wall has less room to move, so each push takes more effort and achieves less. Our post on pressure and Boyle’s law shows how quickly this happens.

Every push costs oxygen

Contracting your diaphragm and abdominals ten or twenty times on a descent is real work. It uses oxygen and adds tension, both of which shorten a breath-hold. Freediving rewards doing as little as possible, and Valsalva asks you to brace your whole torso every metre.

The risk of forcing a Valsalva

This is the part many beginners never hear about. When the tubes don’t open and you push harder, the pressure in your chest climbs. That pressure is passed on through the fluid around the brain to the fluid of the inner ear. If the middle ear is still at low pressure because it hasn’t equalised, the thin membranes between the middle and inner ear, such as the round window, take the strain.

Diving doctors link forceful Valsalva to inner ear barotrauma. Symptoms include vertigo, ringing in the ears and hearing loss, and they need an ENT promptly, not a wait-and-see approach. Our guide to ear pain after freediving covers the warning signs in more detail.

Safety: Never blow hard to clear your ears. If an ear won’t equalise with a gentle effort, stop the descent, rise a metre or two, try once more gently, and end the dive if it still won’t clear. Vertigo, ringing or muffled hearing after a dive means no more diving and a prompt visit to an ENT.

When Valsalva is perfectly fine

None of this makes Valsalva the villain. It is fine for snorkelling, for gentle feet-first descents in a pool, for scuba divers who descend upright with full lungs, and on a plane coming in to land. The key word is gentle. A soft, early Valsalva is a very different thing from a red-faced shove at 8 metres.

Plenty of new freedivers keep using Valsalva while they learn Frenzel. That is sensible, as long as they descend feet-first and slowly until the new technique is reliable.

A four-week plan for switching to Frenzel

Unlearning a habit takes longer than learning a new one, mostly because under stress your body goes back to what it knows. Expect your first few dives after the switch to slip back into Valsalva. That is normal.

Week	Focus	What to do
1	Isolate the parts	Glottis closures (“uh-oh”), humming to feel the soft palate, silent “K” movements with the nose pinched. Five minutes, twice a day
2	Full Frenzel upright	Nose clip on, hand on belly, three sets of ten gentle equalisations. Belly stays soft
3	Change position	Same sets lying on your back, then with your head hanging off the edge of the bed
4	Water	Feet-first descents down a pool wall or a line with a buddy, then head-first with a slow duck dive

The drills for weeks 1 to 3 are set out in detail in our post on equalisation exercises you can practise at your desk. Don’t rush week 4. A Frenzel that only works at your desk isn’t finished yet.

Further down the line, when your lungs get so compressed that you can’t refill your mouth, Frenzel itself hits a limit and you move on to mouthfill equalisation. That is a problem for later. Get the basic switch done first.

What to check on your next pool session

• Do your first three descents feet-first and notice which technique your body picks when you aren’t thinking about it.
• Put a hand on your belly at the surface and do one practice equalisation before each dive.
• If you catch your stomach tightening at depth, don’t push. Come up and reset.
• Note in your log which ear was slower, and at what depth.

An online community for Indian freedivers is on its way here at freediving.in, so stay tuned.