Four schools of cold therapy.
Wim Hof Method, the Søberg principle, contrast therapy (Fire & Ice), and gradual adaptation. Different mechanisms, different evidence bases, different goals — with the honest comparison of which one suits which member.
Method 01
The Wim Hof Method
Wim Hof, 1990s–present
Cold immersion paired with hyperventilatory breathwork and mindset training.
The most famous cold protocol in the world, made rigorous by the 2014 Kox RCT showing trained subjects could voluntarily modulate their inflammatory response to bacterial endotoxin.
Wim Hof — “The Iceman” — built a method combining three elements: cold exposure (typically cold showers and ice baths), hyperventilatory breathwork (30–40 deep breaths followed by extended breath holds), and mindset training (commitment, focus, conviction).
The method moved from fringe to scientifically credible with Kox et al. (2014, PNAS 111(20): 7379–7384), the first study showing humans could voluntarily train the autonomic nervous system response previously assumed involuntary. 24 healthy young men were randomised; the Wim Hof Method group, after 10 days of training, produced significantly fewer inflammatory cytokines (lower TNF-α, IL-6, IL-8) and reported milder flu-like symptoms when injected with bacterial endotoxin compared to controls.
Subsequent work (Buijze 2019 on rheumatoid arthritis; ongoing trials on autoimmune conditions) has explored the inflammatory modulation in clinical populations. The clinical evidence base is younger than the cold-immersion literature alone, but the direction is promising.
Critical safety note: The hyperventilatory breathwork in WHM is dangerous in or near water. Multiple deaths have occurred from people doing Wim Hof breathing while submerged or in pools. The breathing is always done on land, sitting or lying on solid ground, before any cold-water exposure.
Protocol
Cold exposure (3 min in 10°C water typical) + structured breathwork (30 breaths, hold, repeat 3 rounds) + mindset training. Best learned in a guided setting first. 2–3 sessions per week.
Evidence
Kox et al., PNAS 111(20): 7379-7384 (2014). The most rigorous demonstration of voluntary inflammatory response modulation in healthy adults.
Best for
Members targeting inflammatory modulation, autoimmune support, or those drawn to the structured discipline of a named method. R1SE's Guided Fire & Ice and Wellness Experience sessions include WHM-style breathwork in the prep phase.
Method 02
The Søberg Principle
Susanna Søberg, 2020–present
Minimum-effective-dose cold immersion to sustain brown adipose tissue activation.
The Copenhagen-based research programme that quantified the floor of cold-immersion practice — 11 minutes per week of total immersion at 4–7°C sustains the metabolic adaptations.
Dr Susanna Søberg at the University of Copenhagen published the foundational quantification paper in 2021 (Cell Reports Medicine 2: 100408). The trial measured habituated cold-immersion practitioners and identified the dose at which brown adipose tissue (BAT) activation, insulin sensitivity improvements, and cold-induced thermogenesis were sustained.
The answer — roughly 11 minutes per week of total immersion at 4–7°C, distributed across multiple shorter sessions — became the most-cited dose recommendation in popular cold-therapy guidance. Søberg has also published on the “Søberg principle”: always end on cold, not heat, for the strongest BAT-activation effect (the body interprets the final cold exposure as a sustained signal to upregulate thermogenic capacity).
Søberg's framing has been influential because it answers the question most cold-curious people have: “how much do I actually need to do?” The answer (11 minutes a week, well-distributed) is achievable for working adults and provides clear measurable outcomes. The book Winter Swimming (Søberg, 2022) is the popular extension.
Worth knowing: 11 minutes is the floor for the metabolic signal. The dopamine/mood benefits accumulate with consistent practice regardless of dose; the immune signal (Buijze 2016) appears at much lower doses. Søberg specifically quantified the metabolic floor — not the total benefit envelope.
Protocol
11 minutes per week of total immersion at 4–7°C, spread across 4–5 sessions of roughly 2–3 minutes each. End on cold (not heat) if using contrast therapy.
Evidence
Søberg et al., Cell Reports Medicine 2(10): 100408 (2021). The first rigorous quantification of minimum effective cold-immersion dose.
Best for
Members focused on metabolic health, insulin sensitivity, brown fat activation, and sustainable practice. The default recommendation for most R1SE members targeting the broad cold-immersion benefit envelope.
Method 03
Contrast Therapy (Fire & Ice)
Pre-modern (Finnish + Russian traditions), formalised in modern sports medicine
Alternating hot and cold exposure in structured cycles — sauna → cold → sauna → cold.
The thousand-year-old Finnish and Russian bathing traditions, validated by modern sports-medicine research on circulatory and recovery effects.
Contrast therapy alternates between hot (sauna, hot tub, hot bath) and cold (ice bath, cold shower, cold plunge) exposure in structured cycles. A typical session: 10–15 min sauna, 1–3 min cold, 5 min rest, repeat 3–4 times.
The mechanism combines what each modality does individually plus a pumping effect on the circulatory system — vasodilation in heat, vasoconstriction in cold, repeated — that increases venous return, lymphatic drainage, and microcirculatory function. The combined acute catecholamine release (cold) plus the heat-shock protein and cardiovascular conditioning (heat) tends to produce stronger recovery and subjective wellbeing effects than either alone.
Practical wisdom from Finnish and Russian bathing traditions has been informally validated by modern sports-medicine work on contrast water immersion (CWI). Vaile, Halson and others have published RCTs showing CWI accelerates recovery from heavy resistance training and endurance sessions, with effects exceeding standalone cold or standalone heat.
Important sequencing note: end on cold for maximum BAT-activation effect (Søberg principle), or end on heat for maximum parasympathetic relaxation effect (better for sleep, calmer afterwards). Choose your ending based on goal.
Protocol
Sauna 10–15 min → cold 1–3 min → 5 min rest → repeat 3–4 times. End on cold (BAT focus) or heat (sleep focus) based on goal. R1SE's Fire & Ice service is the structured guided version.
Evidence
Vaile et al., Eur J Appl Physiol 102(4): 447-455 (2008). Buchheit et al., J Sports Sci Med 8(2): 215-219 (2009). Multiple subsequent CWI trials.
Best for
Members targeting maximum recovery effect, circulatory health, and the full sensory ritual of bathing tradition. The R1SE Fire & Ice signature service is built around this method.
Method 04
Gradual Cold Adaptation
Pre-modern, common across diving and outdoor swimming communities
Slow progressive exposure over weeks and months — tolerance builds incrementally without method-specific protocols.
The least-named, least-marketed, most-used approach to cold exposure. Most outdoor swimmers, cold-shower practitioners, and casual users follow this pattern without realising it has a name.
Gradual cold adaptation is what it sounds like: start with brief, less-cold exposure (a cool shower, a 30-second dip), and progressively extend duration and reduce temperature over weeks. No structured method, no specific dose, no formal protocol — just consistent low-stakes practice that builds tolerance and adaptation over time.
The literature for this approach is largely observational (open-water swimming cohorts, cold-shower studies including Buijze 2016) rather than structured RCTs of the “method.” The evidence base is the cumulative effect of consistent practice over months, not any single trial.
Why it works: the autonomic system adapts to cold exposure over weeks regardless of the specific protocol. Heart rate response, breathing control, and subjective cold tolerance all improve with consistent exposure. The cellular adaptations (BAT activation, mitochondrial improvements) follow the cumulative dose more than the structure of any individual session.
Best for: members who've been put off by the “Wim Hof bro” aesthetic or feel they need a named method to start. You don't. Get in cold water consistently. Build tolerance gradually. The benefits arrive regardless of which guru's name is on the protocol.
Protocol
Start with 30 seconds at 12°C; add 15 seconds and/or drop 1°C every few sessions; sustain 2–3 minutes at 4–7°C as ongoing practice. No prescriptive structure beyond consistency.
Evidence
Buijze et al. PLOS ONE 11(9): e0161749 (2016) on consistent cold-shower practice. Open-water swimming literature (Espeland et al., Int J Circumpolar Health 2022) on observational long-term practitioners.
Best for
Members who prefer practice over protocol, who want a low-friction way in, or who've found other named methods off-putting. Quietly the most-used approach among long-term cold practitioners.
Common questions
Pick a method. Pick a session.
Whichever school you align with, we run the practice. Guided Fire & Ice for contrast and WHM-influenced sessions, unguided plunges for sustained Søberg-minimum practice.
Continue Reading
More from the R1SE Ice Bath Library
Ice Bath Knowledge Hub
Every cold-therapy page on the R1SE knowledge library.
ReadThe Science of Cold
Catecholamines, brown fat, immunity, mood — every claim cited.
ReadThe Benefits of Cold
Metabolism, mood, immunity, recovery, focus, resilience.
ReadConditions Cold Helps
Depression, inflammation, insulin sensitivity, recovery.
ReadHow to Cold-Plunge
Temperature, duration, frequency — the 11-min-per-week rule.
ReadTypes of Cold Exposure
Ice bath vs cold shower vs cryotherapy vs cold-water swim.
Read