A big gap on the plateau of C to you on France 5. A bath in a bathtub of ice cubes live in What era (France 2). A stint on Sud Radio, a few podcasts and articles in She or Current wife… Shirtless often, shorts and hat always, Wim Hof was at the end of April on a promotional tour in our country. This Dutchman is known worldwide for his records recorded in Guinness : swimming under the ice (57.5 meters in 2000), freediving in the water of a frozen lake (6.2 minutes in 2002) or even several Bermuda short ascents of the 5,895 meters of Kilimanjaro. Charismatic, loud-mouthed, he is also a star of personal development: 3.5 million followers on Instagram, 2.72 million subscribers to his channel Youtube992,000 on Facebook… Netflix dedicated a documentary to it, and the BBC a reality TV series in six episodes.
To his fans, this sixty-year-old promises that his method – breathing exercises, (very) cold baths and mental strengthening – will bring them well-being, resistance to stress and illness, self-healing abilities and increased concentration. From one media to another, the discourse is well-established. “It’s about entering into a deep connection with one’s physiology”, “what I do is accessible to everyone”… At L’Express, he also claims to be at the origin of a “revolutionary discovery in the understanding of inflammation, which is the cause and consequence of all diseases” (sic). Depressioncancer, autoimmune diseases, Alzheimer’s,Parkinson, heart conditions would, according to him, be accessible to the effects of the cold: “It is a therapeutic means to obtain control of one’s cardiovascular, lymphatic and immune systems”, he explains. Nonsense? Elucubrations? A burning question in reality. Because more and more scientists are wondering about the benefits of cold, and studies on its method have even been published in serious journals.
A guarantee that he uses and abuses, shamelessly mixing proven facts and assumptions, science and pseudoscience. Effective – and profitable. Under the leadership of his eldest son, 26 people work for Innerfire, the company built around “Iceman”. Well-packaged method, ultra-slick site, application, books, pre-recorded courses, training of trainers, offers for companies, expeditions with Wim: the whole range of personal development gurus is available. A model of its kind, even. Better, some 2,000 “instructors Wim Hof” contribute to the dissemination of its precepts, in return for a license. The company does not communicate its financial data and the former trucker assures that he wants above all to “help others”. The Dutch press, however, reported a profit of 4.5 million euros in 2021 for Hof Holding, parent company of Innerfire And according to the Dutch registry, its equity reached 14 million euros in 2022, compared to 2 million in 2018…
Madonna, Lady Gaga, Mbappé or Beckham in ice cube baths
From Hippocrates to the Nordic peoples, interest in cold baths has always existed. But Wim Hof has contributed greatly to the current craze for the practice. On social networks, Madonna, Lady Gaga, Kylian Mbappé and David Beckham show themselves in bathtubs full of ice cubes. If the Dutchman canceled his visit to the Zénith at the beginning of June due to lack of sufficient reservations, the offers of immersion courses in ice water, with or without his method, abound on the Internet, in our country as elsewhere in Europe. Almost everywhere along the coasts or in the mountains, cold water swimming clubs are multiplying. But beyond records or the pleasure of surpassing oneself, does this new fashion really bring health benefits?
Matthijs Kox, a researcher at Radboud University in the Netherlands, was the first to take an interest in the prowess of his compatriot in the early 2010s. He first showed that in the presence of a pathogen, Wim Hof presented a different immune response of what was expected, with few inflammatory markers. The scientist then tested the method on twelve trained volunteers by Hof, compared to twelve untrained subjects. Exposed to the same protocol, with the injection of an attenuated pathogen, the former had fewer signs of inflammation, less fever and higher levels of adrenaline in the blood than the control group.
Interesting, but far from a medical revolution. “Wim is enthusiastic about the anti-inflammatory effects of his method, but it has only been evaluated in healthy subjects exposed to an acute infection,” puts Matthijs Kox into perspective. “We cannot conclude anything about a possible beneficial effect in inflammatory diseases, which are chronic and multifactorial. This makes no sense,” confirms Professor Alain Fischer, immunologist, president of the Academy of Sciences (and columnist at L ‘Express). Following the publications of Matthijs Kox, several other researches were carried out by different teams. A synthesis, published in Plos one in March, indicates that the method could have immunomodulatory effects, to be confirmed by better quality studies.
“More alive”, “more awake”
Scientists have also attempted to evaluate the benefits of immersion and swimming in cold water more broadly. At the Arctic University of Norway, Professor James Mercer has compiled around a hundred studies in a meta analysis published in 2022. He notes potential effects on insulin resistance or body fat composition. “However, they remain small in magnitude, and could just as well be achieved with a healthy lifestyle. But many do not want to hear it,” laments the researcher. Because the practice excites its followers, who say they feel “more alive”, “more awake”, “more energetic”. “From a physiological point of view, this is explained because sudden exposure to cold causes a transient increase in stress hormones, adrenaline, noradrenaline, cortisol,” notes Mike Tipton, professor at the University of Portsmouth (UK). -United).
A great specialist in the effects of cold water baths, this scientist remains skeptical about their alleged benefits. “Most studies are not comparative: wouldn’t we obtain similar results with yoga or cycling? And what are the mechanisms at work: the cold? Physical activity? The fact to be in a group outside? We don’t know,” he emphasizes. This expert also points out the absence of a precise protocol, particularly for exposure times: “An immersion of a few minutes will be positive for the immune system, but it becomes detrimental if it is prolonged.”
Wim Hof continues to try to prove the interest of his “method”. Thanks to funding from Australian billionaire Jeffrey Wilson and his naturopath wife, a large study was carried out on its psychological and cognitive effects. Jemma King, a researcher at the University of Queensland, deployed a rigorous protocol. More than 400 participants divided into three groups (one practicing the Wim Hof method, the other cold showers and the third meditation) were evaluated on a battery of parameters (sleep, cognitive skills, resistance to stress, rhythm cardiac, etc.), but the results are not yet available.
Hypothermia, injuries and “after drop”…
In the meantime, specialists are warning of the dangers of icy water. Immersing yourself in it causes a muscular convulsion which blocks breathing, before leading to an episode of uncontrollable hyperventilation which can lead to loss of consciousness. At the same time, the vessels under the skin close to prevent icy blood from cooling the organs. This vasoconstriction causes a sudden increase in blood pressure, dangerous in cases of cardiac fragility.
The body then begins to tremble to produce heat, before the feeling of cold is replaced by pain. This in turn disappears and bathers find themselves in a deceptive state of well-being: “The internal sensors malfunction and cognitive abilities slow down but the body continues to cool,” warns Benoit Mauvieux, specialist in physiology in extreme environments at the University of Caen. Hypothermia lurks. The cold can also cause lasting and painful lesions tissues and nerves. The risks do not stop when leaving the water because an “after drop” then occurs: the internal temperature continues to plunge, particularly at the level of the heart as the cooled blood irrigates the body. “This can lead to heart pain and discomfort,” warns the researcher.
The danger is greatest during the first immersions but drowning and discomfort can always occur later. An American investigative journalist, Scott Carney, indicates having recorded “several deaths in a context of practicing the Wim Hof method”. Only one has given rise to legal action to date, in the United States – the trial is due to take place this year. Specialists are particularly concerned that some people practice breathing exercises in water, or go into apnea with their faces in cold water. “This increases the risk of arrhythmia and cardiac arrest,” emphasizes Mike Tipton. Wim Hof’s site warns of these dangers, and discourages these practices. “The problem is that there are videos where he himself acts like this…” laments Scott Carney.
For those who would still be tempted, Professor Tipton has written recommendations to minimize the risks: carry out a preliminary medical examination, never practice alone, enter the water very gradually, only wet your face once the thermal shock has passed, exit after ten minutes even if you feel well, do not drive for the next half hour… Failing to improve your health, this will perhaps prevent you from losing your life.
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