It took almost a decade for any scientist to take an ear to Wim’s championing the untapped power of nature, its tremendous potential to heal, make strong and make happy, and how it is readily available to all of us. But then, in 2010, curiosity finally got the best of a group of researchers at University Medical Center Saint Radboud.

They were particularly interested in Wim’s claim of being able to shake off a case of the flu simply through focus and an intensified mode of breathing. In scientific circles, this was a very bold statement, because willfully suppressing symptoms of illness went against everything that was accepted in modern medicine.

When you get sick, your body fights off the bacterial invaders by mounting a defensive army of antibodies and white blood cells. The resulting clash of microorganisms manifests outwardly in symptoms we are all familiar with: fever, chills, muscle aches, nausea.

That so-called auto-immune response is automatic—hence the word auto. It cannot be stopped or suppressed. At least, that was our scientific understanding at the time. But when the doctors at Radboud University injected Wim with Escherichia coli, a toxic compound that would mimic a real bacterial infection—and that should, by all accounts, trigger a strong immune response, along with all the aforementioned symptoms—all Wim experienced was a slight headache that quickly passed.

When they measured Wim’s blood, the inflammatory proteins—the body’s tiny cellular troops—that ought to have been recruited en masse were at only half, to one third of levels normally seen. The researchers were flabbergasted. Wim Hof had done what was believed to be impossible: to voluntarily, without any medication or outside influence, modify his immune response.

When Wim’s superhuman feats were proven to be, in fact, quite human, the scientific community worldwide took notice. If every man, woman and child was able to influence their autonomic nervous system with nothing more than cold water and oxygen, that would have major implications for health and wellness practices—both clinically and at home. The next step was to find out what exactly is going on inside our bodies, on a biochemical level, during Wim Hof Method exercises.

That is what researchers at Wayne State University School of Medicine in Detroit set out to uncover. They invited Wim over to their lab, and put him in a special Avengers wetsuit. The suit was fitted with many little tubes through which water could be pumped at a constant rate. This allowed the researchers to simulate an environment of alternating warm and cold water, while closely measuring body temperature using PET and fMRI scans.

When Wim utilized his breathing method and mental focus, The fMRI scan demonstrated highly elevated activity in the “periaqueductal grey” area of the brain. This brain region stimulates the release of opioids and endocannabinoids—our body’s homegrown painkillers—in order to soften any painful sensation.

Meanwhile, the scans showed less activity in the insular cortex. This area of the brain governs how we experience pain consciously and emotionally. In other words, through his breathing method, Wim was able to stay emotionally calm, and not let the cold water enveloping his body send him into a panic.

As the name of the study suggests, Wim and the Michigan team convincingly showed that you can actively steer both the physiological response to outside stimuli like cold, as well as how you mentally perceive that impulse.

The implications were hard to understate: now that there was scientific proof that combining Wim Hof Method breathing and cold exposure produces endogenous painkillers, it opened the door for the Wim Hof Method to be part of standard treatment protocols for all sorts of pain-related health conditions. What’s more, if we could wilfully modulate our pain response, then we might well also exert greater control over a slew of other ANS-governed processes that were previously thought to be entirely autonomous. Could we voluntarily influence our blood pressure, release of hormones, or nutrient absorption? The results of this study suddenly made that prospect a lot more plausible.

A recent study into Wim Hof Method practice & pain perception cemented the pain-dampening findings of Wayne State University. Researchers used quantitative sensory testing to determine how strongly people experienced pain, and found that pain perception was decreased for the group that was trained in the Wim Hof Method.

As the Wim Hof Method gained recognition as a scientifically validated form of therapy, interest from academics and universities began to grow, both in depth and in scope. The locus of interest also started expanding into the more psychological benefits of the Wim Hof Method.

A couple of researchers from the University of Bayreuth in Germany were interested in the effects of Wim Hof Method practice on perceived stress. They recruited 100 participants, who were divided into 4 groups: a breathing group, a cold exposure group, a group that did both breathing and cold, and a control group. The intervention groups practiced the Wim Hof Method for 14 days, and their perceived stress levels were measured before and afterwards using industry standard PSS-10 and PSQ questionnaires.

Following the already formidable body of evidence on the potential for the Wim Hof Method to alleviate pain, Rehabilitation Research Center Reade — an expertise center for rehabilitation and rheumatology in Amsterdam — wanted to see if Wim’s method would have similar positive effects on people dealing with spinal cord injury.

Spinal cord injury, or SCI, can be a very debilitating condition, especially the more severe forms. Injuries to the spine tend to damage, clamp, or sever critical nerves that in turn govern important brain signalling. When those signals are disrupted, it messes with hormone balance and causes pain, inflammation, and breathing and sleeping problems.

All of these symptoms ultimately lead back to a compromised nervous system, and since Wim Hof Method practice tends to improve autonomic nervous function, the potential to alleviate SCI issues was plain as day.

Academics at Reade set up a pilot study in which they invited a small group of people with SCI to practice the breathing method for a period of four weeks. These people were tested on various parameters, such as lung capacity, blood pressure, energy levels and mood, before and after the trial phase.

As expected, the results were very positive: almost half of the trial participants reported feeling more relaxed, having more energy, and sleeping better. Some noted experiencing less pain or coughing than usual, better energy levels & mood, or used less spasticity medication after the WHM intervention. The participants also reported noticeable improvements in respiratory function and hyperventilation, and hindrance due to spasticity showed a favorable trend. The outcome was so promising that Reade decided to follow the pilot study up with a full-fledged randomized controlled trial, results of which are still pending.

The scientific evidence amassed over the last decade is nothing short of astounding. It's incredibly uplifting to see so many renowned institutions take an interest in the Wim Hof Method, as these studies are critical steps towards Wim’s important method becoming a widely recognized tool in the mainstream health and wellness sphere. We are truly seeing Wim’s mission come to fruition.

Besides forming big steps towards scientific legitimacy, these discoveries also serve to further our understanding of what we are humanly capable of—affirming our innate power to deal with all sorts of illnesses and symptoms, to lift our own mood, boost our energy and get restful sleep—all through nothing but our own body, mind, and Mother Nature.

Beyond the research covered here, there are many more studies that don’t strictly follow exact Wim Hof Method protocols, but that have nevertheless contributed to the overall physiological puzzle of the Wim Hof Method. Meanwhile many more studies are in various stages of development, and we are eagerly anticipating what new insights they will bring. One big upcoming study from the University of Queensland involves more than 400 trial subjects, and is poised to shed decisive new light on the potential for the Wim Hof Method to spread happiness, strength and health across the globe.