Cryotherapy & Recovery

What Is Whole-Body Cryotherapy?

Whole-body cryotherapy (WBC) involves brief exposure — typically 2–4 minutes — to extremely cold air, between -110°C and -140°C, inside a cryochamber. This is distinct from cold water immersion (CWI), which achieves a similar biological response via a different mechanism: WBC works primarily through cold thermoreceptors in the skin, whereas CWI additionally involves hydrostatic pressure and conductive cooling.

The key: it's the temperature signal to the nervous system, not the depth of tissue cooling, that drives most of the benefits.

Norepinephrine: The Primary Driver

The most well-characterised acute effect of cold exposure is a dramatic surge in norepinephrine (NE), a catecholamine neurotransmitter and hormone with potent anti-inflammatory properties.

A foundational study by Westerlund et al. (2006) demonstrated NE increases of 300–400% following WBC sessions. This is significant because norepinephrine:

• Inhibits the NF-κB inflammatory signalling pathway
• Reduces production of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β)
• Constricts peripheral blood vessels, reducing oedema
• Improves focus, attention and mood

The anti-inflammatory effect is the primary reason WBC is used extensively by professional sports teams across the NFL, NBA, Premier League football and Olympic programmes.

The Evidence on Recovery

Bleakley et al. (2012) published a landmark Cochrane systematic review on cold water immersion for post-exercise recovery. Key findings:

• Significant reduction in delayed onset muscle soreness (DOMS) at 24, 48 and 72 hours post-exercise
• Improved perceived recovery compared to passive rest
• Faster return to peak force production

A 2021 meta-analysis in the *British Journal of Sports Medicine* (Malta et al.) found that both WBC and CWI reduced muscle damage markers (creatine kinase, LDH) when applied within 1 hour of high-intensity training.

"Cold water immersion appears to be more effective than other recovery modalities for reducing soreness and improving perceived recovery." — Cochrane Database, Bleakley et al.

Anti-Inflammatory Mechanisms

Beyond norepinephrine, cold exposure exerts anti-inflammatory effects through several pathways:

1. Reactive oxygen species (ROS) scavenging — Brief cold stress upregulates endogenous antioxidant defences, including superoxide dismutase (SOD) and catalase, without causing oxidative damage.

2. Cold shock proteins — Analogous to heat shock proteins, cold shock proteins (particularly RNA-binding motif protein 3 / RBM3) are upregulated by cold exposure. RBM3 has been shown in animal models (Peretti et al., 2015, *Nature*) to protect against synapse loss in neurodegenerative conditions.

3. Vagal tone improvement — Cold stimulation of the vagus nerve via skin thermoreceptors increases parasympathetic activity, reducing systemic inflammatory tone over time.

Pain Reduction

WBC reduces pain through multiple mechanisms:

• Local analgesic effect — Cold slows nerve conduction velocity, reducing the speed of pain signal transmission
• Central sensitisation reduction — Norepinephrine modulates descending pain inhibitory pathways in the spinal cord
• Endorphin release — Cold stress triggers beta-endorphin release, the same pathway activated by exercise

Clinical evidence supports WBC for rheumatoid arthritis, fibromyalgia, and ankylosing spondylitis (Bettoni et al., 2013; Hirvonen et al., 2006).

Important Nuance: Timing Matters

A 2019 study in the *Journal of Physiology* (Fyfe et al.) found that cold water immersion immediately after strength training may blunt hypertrophic adaptations by suppressing mTOR signalling and satellite cell activity. The inflammatory response to resistance training appears to be part of the muscle-building signal.

Practical recommendation:

• Use cryotherapy after endurance training or on rest/recovery days — evidence strongly supports this
• Avoid cryotherapy immediately after heavy resistance training if muscle building is the primary goal
• Optimal window: within 1 hour post-endurance exercise

Protocol

• Temperature: -110°C to -140°C (WBC) or 10–15°C (CWI)
• Duration: 2–4 minutes (WBC) or 10–15 minutes (CWI)
• Frequency: 2–5x per week for recovery; acute use post-competition as needed
• Contraindications: Raynaud's disease, cryoglobulinaemia, severe cardiovascular disease, cold urticaria

The Bottom Line

Cryotherapy has a strong, mechanistically coherent evidence base for pain reduction, anti-inflammation, and post-exercise recovery. The norepinephrine response alone — well-documented at 300%+ elevation — explains the majority of the benefits. Time your sessions appropriately around your training type and the evidence is firmly on your side.