The science behind the Wim Hof Method

The science behind the Wim Hof Method



What "The Iceman" Wim Hof is capable of was long viewed as scientifically impossible. It wasn't until the first Radboud University study in 2011 that things really kicked off.

The study showed that by using his method, Wim was able to voluntarily influence his autonomic nervous system - something which until then was thought impossible. This groundbreaking finding, published in PNAS and Nature, established credibility, quite literally rewrote biology textbooks and piqued scientists’ curiosity.

Since then, many researchers have taken an interest in the potential benefits of the Wim Hof Method. Today, Wim and his team continue to work with research institutions and various promising studies are currently underway.

Radboud University, The Netherlands (2014)

  • Aimed to test if the results from the first study on Wim could be reproduced with a larger group
  • Injected 12 Wim Hof Method practitioners with an endotoxin
  • Results showed that, like Wim, they were able to control their sympathetic nervous system and immune response
  • Anti-inflammatory mediators were ~200% higher, while pro-inflammatory mediators were ~50% lower
  • Potentially important implications for “conditions associated with excessive or persistent inflammation, especially autoimmune diseases.” (2014, Knox et. al.)

Wayne State University, Michigan, USA (2018)

  • Also known as the ‘Brain Over Body’ study
  • Aimed to understand the brain function that allows Wim to withstand extreme cold exposure
  • Wim was put in a special temperature controlled suit and placed in both an fMRI and a PET scanner
  • Results showed activation of areas in the brain associated with pain suppression, self-reflection and well-being, in particular the periaqueductal gray area (PAG)
  • This may have implications for “lifestyle interventions that might ameliorate multiple clinical syndromes.” (2018, Muzik et. al.)


We are continuously working with research institutions worldwide to explore new and exciting potential applications of the Wim Hof Method. A timeline of the scientific research to-date, along with links to the scientific papers can be found below.

Present - Ongoing Research

  • Inflammation & Pain In the Netherlands, Radboud University Medical Center in Nijmegen is completing a new study about the effects of the various components of the WHM on inflammation and pain.
  • Metabolic Activity Kenkodo Metabolomic Discoveries in Germany is working closely with Radboud UMC. They are analyzing blood samples that have been taken by Radboud UMC in previous studies. Using this data, they seek to deepen the understanding of the metabolic activity in blood cells when practicing the WHM. Its various parameters can provide new insight into shifts in metabolic rate.
  • Brain Activity Wayne State University in Michigan, USA, is measuring the effect of the WHM on brain activity. This research consists of 2 parts: 1. Effects of isolated cold exposure 2.Effects of cold exposure combined with WHM breathing exercises and mind-set.
  • WHM on Mental Health and Stress Resilience University California San Fransisco is measuring the WHM on mental health and stress resilience.


  • Article: “Brain over body”–A study on the willful regulation of autonomic function during cold exposure Authors: O. Muzik, K. Reilly, V. Diwadkar - Wayne State University School of Medicine Summary: In this paper, a brain imaging study was conducted to measure the relative contributions of the brain and the periphery that endow the Iceman to withstand the cold using his Wim Hof Method techniques. The results provide compelling evidence for the primacy of the brain (CNS) rather than the body (peripheral mechanisms) in mediating the Iceman's responses to cold exposure. They also suggest the compelling possibility that the WHM might allow practitioners to develop higher level of control over key components of the autonomous system, with implications for lifestyle interventions that might ameliorate multiple clinical syndromes.


  • Article: Voluntary Activation of The Sympathetic Nervous System and Attenuation of the Innate Immune Response In Humans Authors: M. Kox, P. Pickkers et al. - Radboud University Medical Center (published in PNAS) Summary: In this paper, the effects of the Wim Hof Method on the autonomic nervous system and innate immune response are evaluated. A group of twelve people was trained with the Wim Hof Method before undergoing an experiment to induce inflammation, normally resulting in flu-like symptoms. Compared to a control group who were not trained in the Wim Hof Method, the trained participants showed fewer flu-like symptoms, lower levels of proinflammatory mediators, and increased plasma epinephrine levels. In conclusion, the trained group was able to voluntarily activate their sympathetic nervous system.
  • Article: Controlled Hyperventilation After Training May Accelerate Altitude Acclimatization Authors: G. Buijze, M.T. Hopman Summary: This report deals with the effects of the Wim Hof Method on acute mountain sickness (AMS). During an expedition to Mt. Kilimanjaro, a group of 26 trekkers who were trained in the Wim Hof Method used the breathing techniques to largely prevent and, if needed, reverse symptoms of AMS.
  • Article: Frequent Extreme Cold Exposure and Brown Fat and Cold-Induced Thermogenesis: A Study in a Monozygotic Twin Authors: J. Vosselman, W.D. van Marken-Lichtenbeld - Maastricht University Medical Center Summary: This study tested the effects of a lifestyle with frequent exposure to extreme cold on brown adipose tissue (BAT) and cold-induced thermogenesis (CIT). The experiment compared Wim Hof, who is used to extreme cold exposure, to his monozygotic twin brother who isn’t. Both used a g-Tummo like breathing technique. The results showed no significant difference in BAT or CIT between the two subjects. However, Wim’s core temperature dropped less compared to his brother and his subjective response to the cold temperature was more positive. Furthermore, the body heat generated of both brothers was considerably higher than the average person. Thus, it seems that g-Tummo like breathing during cold exposure might cause additional heat production.


  • Letter: Blood tests during meditation and breathing exercises in New York led by Dr. K. Kamler & G. Stewart Summary: During Wim’s world record attempt of full ice immersion wearing only shorts, he swallowed a vital sense monitor capsule to measure his core temperature. His core temperature started at 98.6 °F and dropped to 88 °F after 75 minutes of cold immersion. Remarkably, his temperature rose again to 94 °F within the next 20 minutes. Standard medical dogma states that once your core temperature falls below 90 °F, your body is not able to warm itself again. Thus, if no external source of heat is provided, your temperature will continue to spiral downward and you will eventually die of hypothermia. However, Wim proved he was able to raise his core temperature from 88 °F to 94 °F by using the Wim Hof Method techniques.