There's something almost philosophical about watching Wim Hof try to explain himself to a skeptical television presenter. For thirty years, the medical establishment told him what he was doing was impossible. The autonomic nervous system is autonomous — the name says it all. You don't consciously control your heart rate, your immune response, your inflammatory cascade. That's not how biology works.
Except it turns out that's not quite right. The Radboud University study changed everything. Twenty-four healthy young men, half trained in the Wim Hof Method, all injected with E. coli endotoxin. The untrained group experienced what you'd expect — fever, chills, fatigue, nausea. The trained group? Minimal symptoms. Measurably different immune responses. That's not anecdote. That's a controlled experiment with a clear result.
The core claim is this: through deliberate breathing and cold exposure, you can voluntarily influence systems your body normally runs on autopilot. The mechanisms involve the sympathetic nervous system — the breathing techniques trigger a controlled adrenaline release, which modulates the inflammatory response before it gets out of control.
We have dozens of articles in our knowledge base that circle this same finding from different angles. The 2014 PNAS paper Huberman frequently references is the same Radboud study Hof is talking about here. What's interesting is how consistent the mechanism is across the literature. Cyclic hyperventilation raises blood pH, alkalizes the system, triggers catecholamine release. Your sympathetic nervous system fires. In that state, inflammation is actively suppressed — not by willpower, but by biochemistry you initiated through breath.
The cold exposure piece works through a different pathway but lands in the same territory. Norepinephrine spikes on cold immersion. Immune cells activate. Done regularly, the system becomes more responsive, more calibrated. Less reactive to minor stressors. More capable of mounting a genuine defense when one is needed.
The scientific community no longer disputes that the method produces measurable physiological effects. What remains contested is the scope of the claims. Rheumatism, cancer, depression — Hof mentions all of these in the opening segment. The mechanistic story for immune modulation is solid. The clinical evidence for specific disease outcomes is still thin. That distinction matters. This is a powerful tool for resilience and baseline health. It is not a replacement for medical care.
If you're new to this: begin with the breathing. Thirty to forty deep cycles, breath hold, recovery breath. Do it on an empty stomach, lying down. Notice what happens to your body. Then, after a few weeks of that, begin shortening your morning shower with thirty seconds of cold at the end. Build from there. The cold without the breathwork is just uncomfortable. The breathwork primes the system. Together, they compound.
Hof calls depression "disease number one" — and he's not wrong by the numbers. What struck me reading across our research library is how directly the inflammation-immunity connection links breathwork to mental health. Chronic low-grade inflammation is now understood to be a significant driver of depression. The same immune pathways the Radboud study showed Hof's trainees could modulate — interleukin signaling, inflammatory cytokines — are the pathways implicated in treatment-resistant depression. The breath isn't just a relaxation tool. It may be a direct lever on the neuroinflammatory processes underlying mood disorders. That's not woo. That's immunology.