There is little good-quality evidence to support Wim Hof鈥檚 claims that controlled breathing and cold exposure have widespread health benefits. In the first review into Wim Hof鈥檚 Method, researchers found that just a few small studies support his claim that these techniques lower inflammation, with other experiments failing to back up that his methods improve athletic performance.
Also known as The Iceman, Hof claims his so-called three pillars 鈥� controlled breathing, cold therapy and 鈥渃ommitment鈥� 鈥� can benefit everything from our immune health and energy levels to sleep quality and creativity.
To uncover if any evidence supports this, at the University of Warwick, UK, and her colleague Omar Almahayni reviewed eight studies, which were published in peer-reviewed journals and had what they deemed to be a good design. The first four of these explored his breathing and cold therapy techniques, while the other four only tested his breathing methods 鈥� , holding the final exhale for as long as you can and then holding the next inhale for around 15 seconds, repeated three to four times.
Advertisement
Of the first four studies, two linked Hof鈥檚 methods to reduced inflammation. In one of these studies, half of the 24 participants carried out the techniques for around one week, which included a daily practice of standing barefoot in snow for up to half an hour, submerging themselves in icy water and hiking a snowy mountain in just shorts and shoes.
At the end of the experiment, the researchers injected all of the participants with a bacterial protein that is known to provoke an inflammatory immune response. By analysing their blood samples, the team found that those who carried out Hof鈥檚 methods generated lower levels of inflammatory proteins, compared with those not doing the techniques.
However, Hof was involved in this research, which 鈥渕ay give rise to conflicts of interest in the pursuit of both an evidence base and a commercial opportunity鈥�, according to Hammond and Almahayni. But at Radboud University in the Netherlands, an author of the study, doesn鈥檛 think this was an issue. 鈥淚n a follow-up study, we showed that training by an independent trainer achieves similar effects,鈥� he says.
The two studies also didn鈥檛 look at some important aspects of inflammation, such as immune cell activity, and only analysed it over the short term, by injecting the participants with a bacterial protein, says at Queensland University of Technology, Australia. 鈥淭here is no evidence that the Wim Hof Method reduces chronic inflammation, and more research is needed that includes individuals with different types 鈥� and severities 鈥� of inflammation.鈥�
Hammond and Almahayni also assessed whether Hof鈥檚 breathing method alone enhances our ability to exercise, another of his claims. Of the studies that investigated this, none found an effect on how much air entered and left the participants鈥� lungs while exercising, which is sometimes used as a marker of athletic performance. What鈥檚 more, 鈥渘one of the studies compared the Wim Hof Method with other methods of enhancing exercise performance, such as a warming up鈥�, says Peake. Hof鈥檚 other claims, such as improving sleep quality, weren鈥檛 assessed in the studies.
More than 80 per cent of the studies鈥� participants were male, making it hard to generalise the results to the wider population, according to Hammond and Almahayni. Overall, the evidence to support Hof鈥檚 approach is 鈥渘ot strong at all, in my opinion鈥�, says Peake. 鈥淭he take-home message from the review is that there is insufficient evidence for the effectiveness of the Wim Hof Method to support widespread adoption.鈥�
From a safety perspective, cold therapy has been linked to and . 鈥淭here could be medical risks associated with extreme cold exposure for people with pre-existing risk factors,鈥� says Peake. For example, sudden exposure to extreme cold temperatures can increase the risk of heart-related events in particularly at-risk people, he says.
Hof didn鈥檛 respond to a request for comment.
medRxiv
