Wim Hof

Wim Hof (1959–present), the Dutch “Iceman,” is an athlete and self-experimenter who developed the Wim Hof Method — a combination of cyclic hyperventilation-style breathwork, cold exposure, and focused commitment/meditation — and used it to perform extreme feats (long ice immersions, a barefoot half-marathon on snow, climbing high on Everest in shorts) while claiming voluntary influence over normally automatic bodily processes.

Crucially, his claims have been partly tested: a 2014 study (Kox et al., PNAS) showed that Hof and trained followers could, via his method, voluntarily activate the sympathetic nervous system and attenuate their immune/inflammatory response to an injected endotoxin — a result long assumed impossible for conscious control.

Hof is an unusual partly-validated node in the neuroscience-of-practice strand: he embodies the mind-power aspiration of conscious control over the body, and unlike most such claims, a core piece has peer-reviewed support showing that learned breathing and mindset can modulate the autonomic nervous system and inflammation.

For the archive he is a vivid bridge between “mental/breath practice changes physiology” and rigorous measurement. The honest framing keeps two cautions:

(1) the demonstrated mechanism is largely physiological — controlled hyperventilation altering blood gases and stress hormones — not paranormal mind-over-matter; and (2) the breathing carries real risks (shallow-water blackout if done near water; never in/under water), and broader health claims outrun the evidence.

Tier: partly-validated practice (legitimate core, over-claimed periphery).