WHM Glossary

The core breathing exercise of the Wim Hof Method consists of three phases: 30–40 deep breaths (hyperventilation), followed by retention (breath hold after the exhale) and finally a recovery breath (inhale deeply, hold for 15 seconds). A typical session includes 3–4 rounds.

A shift of blood pH toward the alkaline side caused by the rapid breathing phase of the WHM. CO₂ levels drop and pH rises above 7.4. This leads to increased pain tolerance, tingling in the extremities and a sense of lightness.

The highest certification level of the Wim Hof Method, awarded by Inner Fire B.V. (Wim Hof's organisation). An Advanced Instructor is authorised to independently lead all WHM workshops, retreats and courses – including introductory courses, advanced courses and intensive retreats.

Synonym for → Retention. The deliberate holding of the breath after the exhale. Duration: typically 1–3 minutes. Creates a state of reduced CO₂ concentration and increased oxygen utilisation at the cellular level.

The number of breaths per minute. At rest: 12–20 breaths/min. During the WHM breathing phase, the rate is deliberately increased (30–40 breaths in rapid succession). After retention, it drops noticeably during recovery – a sign of parasympathetic activation.

The self-regulating part of the nervous system that controls heart rate, blood pressure, digestion and immune response. It consists of the sympathetic (activation) and parasympathetic (recovery) nervous system. The WHM is one of the few proven methods by which people can voluntarily influence the ANS.

Stress hormone released by the adrenal glands during cold exposure and intensive breathwork. Temporarily increases heart rate, alertness and energy supply. In the WHM context, adrenaline is used intentionally: the controlled adrenaline release through cold and breathwork trains the nervous system to become more stress-resistant – without the negative long-term effects of chronic stress.

The advanced course of the Wim Hof Method for participants with Fundamentals experience. Content: more intensive breathwork, brown fat activation, guided ice bath and scientific deep dive. Price: 149 € / person. Prerequisite: completed Fundamentals Workshop.

Brown Adipose Tissue – thermogenic fat tissue activated by cold exposure. Unlike white fat, BAT generates heat (thermogenesis) by burning fatty acids and glucose. Regular cold bathing measurably increases BAT activity.

Umbrella term for conscious breathing practices. In the WHM context, breathwork refers specifically to the WHM breathing technique. Breathwork can reduce stress, sharpen focus, influence the acid-base balance and improve mood.

Burnout is caused by chronic stress, persistently elevated cortisol and an overactivated sympathetic nervous system. The WHM can support burnout prevention: cold exposure lowers chronic inflammatory markers, breathwork trains conscious stress regulation, mental training strengthens resilience. Regular practice improves the ability to switch between tension and recovery – a core skill for burnout prevention.

The body's ability to tolerate high CO₂ concentrations in the blood without triggering the breathing reflex. Regular WHM breathing exercises improve CO₂ tolerance – a marker of endurance, stress resilience and breath control. → Train your CO₂ tolerance

→ Cold Exposure. Refers to deliberate, controlled contact with cold – from a cold shower (15–60 sec.) to an ice bath (2–5 min. below 10 °C).

Neurotransmitter of the reward system. Cold exposure (14 °C water) raises dopamine levels by up to 250 % (Šrámek et al., 2000). This increase is more sustained than with other stimuli and explains the euphoria and improved motivation after an ice bath.

Bathing in ice-cold water – ideally below 10 °C. The most intense form of cold exposure in the WHM. Promotes the release of noradrenaline, activates brown adipose tissue and strengthens mental resilience. Recommended duration for beginners: 1–2 minutes.

The term for retention after the exhale. Unlike inhale retention (holding after the inhale), the WHM retention is performed exclusively after exhaling.

Container for cold baths – ranging from simple plastic boxes to dedicated cold plunge tubs. For home use, a large plastic tub (approx. 200–300 litres) filled with tap water and ice is sufficient. Target temperature: 8–12 °C. In WHM courses the ice tub is used as the first controlled cold confrontation. Beginner tip: 1–2 minutes, practise the breathing technique beforehand.

The body's own peptides with pain-relieving and mood-lifting effects. Released by physical stress – including cold exposure and intensive breathwork. The euphoria after an ice bath is partly attributable to elevated endorphin and dopamine levels.

Persistent activation of the immune system, associated with arthritis, diabetes and depression. The WHM shows anti-inflammatory effects: cold exposure lowers TNF-alpha, noradrenaline inhibits inflammatory cascades. Regular practice can reduce chronic inflammatory markers.

The introductory course to the Wim Hof Method. Content: WHM breathing exercises (2–3 live rounds), theory on cold exposure, first cold confrontation (ice tub or cold shower) and mental focus techniques. Suitable for all beginners with no prior experience.

The rapid, deep breathing phase of the WHM (30–40 breaths). Significantly lowers CO₂ levels (while oxygen saturation remains high) and shifts pH toward the alkaline (alkalosis). In the WHM context it is performed deliberately and in a controlled manner – not to be confused with uncontrolled hyperventilation from panic.

Measure of the variability in the time intervals between heartbeats. A high HRV is considered a sign of good heart health and stress resilience. WHM practice – in particular breathing exercises and cold exposure – can demonstrably improve HRV, indicating stronger vagus nerve activation.

A Tibetan Buddhist meditation technique that Wim Hof integrated into his method. Tummo enables conscious regulation of body heat through a combination of breathwork and visualisation. Wim Hof learned this technique from Tibetan monks.

Studies at Radboud University (2014) demonstrated for the first time that WHM practitioners can voluntarily influence their autonomic nervous system and immune system. In a controlled endotoxin injection, WHM participants produced fewer inflammatory markers and fewer symptoms than the control group.

The easiest entry point into cold exposure – doable every day, no equipment needed. Recommendation for beginners: switch to cold after a warm shower, hold for 20–30 seconds, and gradually increase to 60–90 seconds daily. Effects: noradrenaline boost, improved circulation, increased alertness and mood uplift. The cold shower is step 1 in the WHM progression model: cold shower → ice tub → ice bath in natural bodies of water.

The second pillar of the Wim Hof Method: deliberate, controlled contact with cold. Stages: 1) Cold shower (15–60 sec., entry level) → 2) Ice tub (up to 10 °C, 2–5 min.) → 3) Natural bodies of water / snow bathing. Promotes thermogenesis, noradrenaline release and mental resilience.

The body's initial stress response to sudden cold: adrenaline release, increased heart rate, involuntary hyperventilation. With regular practice the cold shock diminishes – the body adapts. The WHM breathing technique helps to control the cold shock response.

The primary stress hormone. Chronically elevated cortisol is associated with inflammation, sleep problems and burnout. WHM practices – in particular cold exposure and breathwork – can increase stress resilience over the long term and thereby reduce cortisol spikes.

Cryotherapy (cold chamber, −100 to −140 °C, 2–3 min.) and the WHM ice bath (water, 8–12 °C, 2–5 min.) differ fundamentally: water conducts heat approx. 25× more efficiently than air, which is why a 10 °C ice bath is physiologically more effective than a cold chamber. The ice bath costs a fraction of the price and can be reproduced at home. In the WHM context, water immersion is preferred – the effects on noradrenaline, BAT and the immune system are better documented.

Synonym for → Ice bathing. Bathing in cold water below 15 °C; from 10 °C it is referred to as an ice bath. Cold baths activate the immune system, promote the release of noradrenaline and dopamine. Beginner tip: 1–2 minutes at 10–15 °C.

Umbrella term for all therapeutic applications of cold – from cryotherapy (cold chamber at −110 °C) to the WHM ice bath. In the WHM context, cold therapy refers to the systematic, controlled use of cold to promote thermogenesis, immune function and mental strength.

A system built on three pillars: 1) Breathwork (controlled hyperventilation + retention), 2) Cold exposure (cold shower to ice bath) and 3) Mental training (focus, visualisation, commitment). Developed by Wim Hof ("The Iceman") and scientifically studied, among others, by Radboud University Nijmegen.

The third pillar of the WHM: mental focus and commitment. Encompasses mindfulness, visualisation and the conscious decision to step outside your comfort zone. According to Wim Hof, the mind is the "gateway" to all physical transformations.

Your mental attitude – closely linked to the third pillar of the WHM. In the WHM context, mindset means the ability to deliberately step outside your comfort zone, maintain focus and trust your own body. According to Wim Hof, every transformation begins in the mind. Regular cold exposure is direct mindset training.

The powerhouses of the cell – they produce ATP (energy) through cellular respiration. Cold exposure and intensive breathwork increase mitochondrial efficiency. Brown adipose tissue has an especially high density of mitochondria. Long-term WHM practice can improve mitochondrial density and function.

Hormone and neurotransmitter that rises by up to 300 % through cold exposure (studies). It has anti-inflammatory effects (inhibits TNF-alpha), mood-lifting effects (acts as a natural antidepressant), enhances focus and dampens pain. A key mechanism behind WHM's effects.

The "rest-and-digest" branch of the autonomic nervous system. After a WHM breathing exercise and cold confrontation, a strong parasympathetic rebound (relaxation response) often follows. The WHM trains the ability to consciously switch between sympathetic activation and parasympathetic recovery.

Measure of the acid-base balance of the blood (normal range: 7.35–7.45). During the WHM breathing phase, the CO₂ drop causes pH to rise toward 7.6–7.8 (mild alkalosis). This affects pain perception, muscle function and the nervous system.

The breath hold after the exhale – the second part of every WHM breathing round. Duration: typically 1–3 minutes (depending on experience). During retention, CO₂ drops to minimal levels while O₂ levels remain surprisingly high. The body enters an altered physiological state with increased stress tolerance.

The final breath of every WHM breathing round: after retention, inhale deeply and hold for 10–15 seconds, then exhale. Normalises CO₂ levels and initiates the recovery phase. After the recovery breath, an optional next round begins.

The "fight-or-flight" branch of the autonomic nervous system. The WHM is one of the few proven methods by which people can voluntarily activate the sympathetic nervous system (Radboud study 2014). This ability increases stress resilience and adaptability.

The foundation of the method: 1) Breathwork – the specific WHM breathing exercise, 2) Cold exposure – from the cold shower to the ice bath, 3) Mental training – focus, commitment and visualisation. All three pillars work together and reinforce each other.

Neurotransmitter that regulates mood, sleep and appetite. Cold exposure and physical activity can raise serotonin levels. Serotonin is one of the factors that contribute to improved mood and stress resilience after cold baths.

Regular WHM practice can improve sleep quality: breathing exercises activate the parasympathetic nervous system and lower heart rate, making it easier to fall asleep. Cold exposure in the evening is not recommended (increased alertness from adrenaline) – morning or midday is better. Studies show that elevated noradrenaline levels from cold baths can positively influence sleep architecture over the long term.

The ability to cope with stressful situations without lasting impairment. The WHM trains stress resilience directly: cold exposure creates controlled stress that the body learns to regulate better through practice. Regular practice durably changes the stress response of the autonomic nervous system.

The body's own heat production, which is increased by cold exposure. Activates brown adipose tissue (BAT), muscle shivering and hormonal processes. Regular cold exposure improves thermogenesis efficiency – the body learns to produce heat faster and more effectively.

See → Inner Fire. A Tibetan meditation technique that Wim Hof integrated into his system. "Tummo" means "Inner Fire" in Tibetan.

The longest cranial nerve and the main component of the parasympathetic nervous system. It influences heart rate, digestion, immune response and mood. The WHM breathing exercise – in particular the recovery phase – stimulates the vagus nerve and can improve heart rate variability (HRV).

Dutch extreme athlete (*1959), known as "The Iceman". Holds multiple world records: longest time in ice (1 hr. 52 min.), climbing Mount Everest in shorts to an altitude of 7,400 m, marathon in the desert without water. Developed the Wim Hof Method named after him, based on Tibetan Tummo meditation, yoga and cold adaptation.

Abbreviation for Wim Hof Method. Official abbreviation of the method developed by Wim Hof and licensed by Inner Fire B.V. WHM instructors are certified by Inner Fire B.V.

The official app of the Wim Hof Method for iOS and Android. Contains guided breathing exercises, daily cold challenges and tracking functions for retention times. Recommended for getting started with daily WHM practice between courses.

The official training pathway to become a Wim Hof Method Instructor, run by Inner Fire B.V. Levels: Level 1 Instructor, Level 2 Instructor, Advanced Instructor (highest level). Certified instructors are listed on the official WHM website and are permitted to offer workshops independently.