The Science behind the Wim Hof Method

The start of scientific research

What Wim is capable of was long viewed as scientifically impossible. In 2007 the first scientific analysis was done at Feinstein Institute in New York. In 2011, the University Medical Center St. Radboud in Nijmegen really got the ball rolling.

After running several tests they couldn’t but admit that Wim and others are able to voluntarily influence the Autonomic Nervous System. Something which up until then was thought impossible, through the Wim Hof Method. This groundbreaking finding, published in PNAS and Nature, established credibility and bred curiosity among academia. Increasingly, researchers across a wide range of disciplines have since taken an interest, and various promising studies are currently underway.


Download a comprehensive document detailing the science behind the Wim Hof Method.


Motivation and Experiences of WHM Practioners

RMIT University in Australia has conducted a survey study, exploring the motivation and experiences of Wim Hof Method practitioners worldwide. This will offer insight into 1) the positive impact of practicing the WHM on health & wellbeing and 2) any potential adverse effects, which in turn improves safety protocols. The data is currently being analyzed.

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.

Auto-immune Disease

The Amsterdam Medical Centre (AMC) in the Netherlands is conducting a study into the effects of the WHM on inflammation and quality of life of people with Spondylitis.

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


>>>  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 Univeristy 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: The Role of Outcome Expectancies for a Training Program Consisting of Meditation, Breathing Exercises, and Cold Exposure on the Response to Endotoxin Administration: a Proof-of-Principle Study

Authors: H. van Middendorp, M. Kox, P. Pickkers, A.W.M. Evers – Radboud University Medical Centre

Summary: This paper adds to a previous study, published in 2014, on the ability to voluntarily influence the physiological stress response in healthy men to experimentally induced inflammation, after WHM training. It is a proof-of-principle study that investigated how one’s expectancies might play a role in treatment outcome. Indications were found that generalized outcome expectancy optimism is a potential determinant of the autonomic and immune response to induced inflammation after training.


>>>  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.


>>>  Article: The Influence of Concentration/meditation on Autonomic Nervous System Activity and the Innate Immune Response: A Case Study

Authors: M. Kox, M. Hopman, P. Pickkers. et al. – Radboud University Medical Center

Summary: This case-study research was conducted after Wim Hof claimed he could influence his autonomic nervous system and thereby his innate immune response. His inflammatory response was measured during an 80-minute full body ice immersion and practicing the Wim Hof Method concentration technique. In addition, an endotoxemia experiment was conducted to study Wim’s in vivo innate immune response. The results showed how the techniques of the Wim Hof Method seemed to evoke a controlled stress response. This response is characterized by sympathetic nervous system activation, which seems to attenuate the innate immune system. Here, Wim Hof proved he was able to influence his autonomic nervous system.


>>>  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.


Study: Blood tests during meditation and breathing exercises Feinstein Institute

led by Dr. K. Tracey


2015 – Biology Now – Chapter 22 Wim Hof and the endocrine-immune system