Fast and activating

Wim Hof method: what the rounds do to your body

By GyroscopeUpdated November 15, 202615 sources

Family

Fast and activating

Breaths

30 breaths a round, speed up to you

Carbon dioxide

Falls

How well tested

Weak

Risk

High, read the safety part

Timer

None, on purpose

Wim Hof breathing is 30 big breaths in a row, a hold on empty lungs until you need air, then one deep breath held for 15 seconds, done three or four times. It blows off carbon dioxide, drops your oxygen during the hold and sends adrenaline up, which is why you feel tingly during it and wired after. We’d use it now and then for a jolt of energy, lying down, and never as a way to calm down or anywhere near water.

Most people meet the method as a package of ice baths, a Dutchman climbing a snowy mountain with no shirt on, and a famous study that seemed to show you could tame your immune system by breathing. The breathing gets the credit for all of it. Online, the rounds get described as flooding you with oxygen, and the strangely easy hold at the end feels like proof.

The famous study did find something real, but it trained people in breathing, cold and meditation all at once, and the breathing works by setting off a stress response. The easy hold is the part people get backwards. It feels easy because the urge to breathe has been turned down, while the oxygen in your blood can fall to about half of where it started.

What it is and where it comes from

Wim Hof, born in 1959, is a Dutchman known as the Iceman. Guinness World Records credits him with 18 record titles. In 2000 he swam 57.5 meters under ice on a single breath. In 2007 he ran a half marathon barefoot on ice and snow in 2 hours 16 minutes. He broke the record for full-body contact with ice 15 times, and his best was 1 hour 53 minutes in 2013 (other people have since stayed in longer).

Scientists got involved in 2012. Doctors at Radboud University in Nijmegen, in the Netherlands, put Hof in ice for 80 minutes, and later injected him with a piece of bacteria that normally brings on a few hours of fever and aches. While he practiced his concentration and meditation technique, his adrenaline rose, and his cortisol went higher than in any of the 112 volunteers they’d tested before. His inflammation and symptoms were very low. The doctors described it as a controlled stress response, and two years later they tested whether other people could learn it.

The method he teaches today combines breathing, cold exposure and meditation. Some people call Hof a practitioner of tummo, the Tibetan inner fire practice. The method’s own site calls the two comparable but different, and says his method comes mainly from what he calls “cold hard nature”. Tummo has the comparison.

How to do it

These are the method’s own instructions.

1. Lie down or sit on the floor. A bed, a couch or a mat, somewhere you could tip over without hitting anything. Never in a bath, a pool, the sea, a hot tub, a cold plunge or a car.
2. Take 30 big breaths. Breathe in deeply through your nose or mouth, letting your belly push out, then let the air fall out through your mouth without forcing it. The method leaves the speed up to you.
3. Hold on empty. After the last breath, let it go and hold with empty lungs until you feel the urge to breathe. Breathe when it comes. There’s no time to beat.
4. Take one recovery breath. Breathe in fully, hold it for 15 seconds, then let go. That’s one round.
5. Do three or four rounds, then stop. Go back to normal breathing.

The method’s page says you may feel lightheaded and tingly, and that done hard for several rounds the breathing can make you pass out. Its FAQ says that fainting while lying down means you went a little too far.

A simple way to picture it

Your urge to breathe works like a fuel light wired to the exhaust pipe instead of the tank. It mostly reacts to carbon dioxide, the gas you breathe out. Thirty big breaths clear the exhaust, so the light stays off for a long time, even while the tank (your oxygen) runs down at the usual speed.

What happens in your body

Big breaths, one after another, move far more air than your body needs. Carbon dioxide leaves your blood faster than your cells make it, and your blood turns more alkaline. In the 2022 Dutch study, blood pH rose from about 7.4 to about 7.7 within 15 minutes of the breathing. Low carbon dioxide narrows the blood vessels in your brain, so less blood reaches it and your head goes light. MedlinePlus lists tingling and muscle spasms in the hands and feet as symptoms of breathing off too much carbon dioxide too.

Then comes the hold. Normally you can’t hold your breath until you pass out, because a strong reflex forces the next breath first. Low carbon dioxide is one of the things known to stretch a hold out, so after 30 big breaths the urge arrives much later. Your body keeps using oxygen the whole time. In the 2014 study, the trained men’s blood oxygen typically dropped to around 50 percent for a short time at the bottom of each round. What is low blood oxygen? explains how far below normal that is.

The stress response drives the famous results. The breathing sets off your stress system and adrenaline pours out. In the 2022 study, adrenaline roughly doubled after half an hour of the breathing. A burst of adrenaline turns down some of the immune system’s inflammatory signals. What happens in a fast breathing session?, carbon dioxide and breath holds have the long version.

What the evidence shows

In 2014, the Nijmegen team split 24 healthy young Dutch men into two groups of 12. One group trained for 10 days with Hof and three of his instructors. Four days in Poland included standing barefoot in snow, daily dips in near-freezing water and a bare-chested hike in the snow, and then they practiced at home. The other group didn’t train. Then everyone got the same injection of bacterial toxin.

The trained men’s adrenaline shot up. Their main anti-inflammatory signal came out earlier and ended up 194 percent higher, three inflammatory signals were 51 to 57 percent lower, and their worst flu-like symptoms were 56 percent milder. Their cortisol was no different from the untrained men’s during the breathing, but it settled back faster. The limit is that 12 men did three things at once, so nobody could say which part did the work.

In 2022, the same team pulled the parts apart. First 40 men learned two versions of the breathing, one with the long hold on empty and one without. Both raised adrenaline about the same, whoever taught them and however long they trained. The long hold dropped oxygen sharply, so the team used the version without it next, and wrote that the hold may be less preferable for safety.

Then 48 men were split into four groups, for cold training only, breathing only, both, or neither. After the toxin, cold training alone did little to inflammation. Breathing alone lowered some inflammatory signals, and breathing plus cold worked best. Breathing alone didn’t make the worst symptoms milder, though cold training did, and all three trained groups got better faster than the men who didn’t train.

At Stanford in 2023, 33 people did a short version (three rounds of 30 breaths and a 15-second hold on empty) five minutes a day for a month. Mood after each session rose about as much as with cyclic sighing, but anxiety fell about half as much, and resting heart rate and HRV didn’t change.

In the review, most trials compared the method with doing nothing, and the volunteers always knew which group they were in. Whether the method helps people with inflammatory or autoimmune disease over months is still unknown, and the 2014 team said so themselves.

Who should skip it

• Sitting or lying down only. On a bed, a couch, a mat or the floor.
• Never in or near water. No bath, pool, sea, hot tub or cold plunge, and never right before swimming or diving. The method’s safety page says never to attempt the exercises before or during diving, driving, swimming or taking a bath. Its FAQ says to breathe normally in cold water.
• Never driving, or anywhere passing out could hurt you.
• Skip it entirely if you’re pregnant, or have epilepsy, coronary heart disease, a history of heart failure or stroke, kidney failure, cold urticaria, Raynaud’s (type II), high blood pressure you take medicine for, or a recent operation. That’s the method’s own FAQ list.
• Children under 16 should be supervised by a parent, the FAQ says.

Water is the hard rule because of what doctors call hypoxic blackout, losing consciousness under water after breathing hard first. StatPearls notes it can happen in any body of water at any depth. A CDC report on New York from 1988 to 2011 found 16 people who blacked out under water from breath holding, and 4 of them died. All four were advanced or expert swimmers aged 17 to 22, and all four had hyperventilated on purpose. Chest pain, a racing or uneven heartbeat, or trouble breathing that doesn’t settle means stop and get help.