What it is
Two therapies share the name. Cold-water immersion (the plunge, the ice bath) puts the body in water at 10–15 °C for 10–15 minutes; water conducts heat about 25 times faster than air, so the tissue cooling is deep. Whole-body cryotherapy stands you in a chamber of air or nitrogen vapour at −110 to −140 °C for two to three minutes; the skin cools sharply, the muscle barely at all. Both trigger the same first response — a surge of noradrenaline, a jump in heart rate and blood pressure, vasoconstriction — and they diverge after that: immersion cools muscle and reduces blood flow to it for hours, the chamber mostly produces the hormonal and mood effect.
What the research says
| Use | Evidence grade | What was found |
|---|---|---|
| Delayed-onset muscle soreness | Moderate — Cochrane review (Bleakley 2012) and later meta-analyses | Cold-water immersion reduces soreness at 24–96 hours versus passive rest. Trials are small and hard to blind. |
| Perceived recovery and next-day performance in competition | Moderate | Useful between matches or heats when the goal is to perform again soon, not to adapt. |
| Strength and muscle growth after resistance training | Strong, and negative — Roberts 2015 (J Physiol), Fyfe 2019, meta-analysis Piñero 2024 | Cold immersion within an hour of lifting reduces the satellite-cell and mTOR signalling and, over 12 weeks, produces measurably less muscle and strength gain than active recovery. |
| Mood, alertness | Early — small trials, large noradrenaline response | A 2–3-fold rise in noradrenaline and a consistent reported lift in mood for hours. Depression trials are pilots. |
| Inflammatory markers (CRP, IL-6) | Early / mixed | Acute drops in some markers in athletes; no consistent change in resting inflammation in healthy adults over weeks. |
| Fat loss, brown fat | Hype | Cold activates brown fat and raises energy expenditure by tens of calories. Trials show no meaningful weight change. |
| Immune function | Early — one Dutch trial (Buijze 2016) | Thirty-second cold showers cut self-reported sick days by 29% with no change in illness days. A small, real, modest effect. |
Protocols that are studied
- Cold-water immersion, recovery. 10–15 °C, 10–15 minutes, to the neck or the chest. Colder is not better; 5 °C for 5 minutes is a different stressor with less data.
- Whole-body cryotherapy. −110 to −140 °C, 2–3 minutes, dry skin, gloves and socks, ears covered. Two to three sessions a week in the recovery studies.
- Cold showers. 30–90 seconds at the end of a warm shower, daily, for the immune and mood findings. The lowest-cost version with the best adherence.
- Weekly dose. Most mood and wellbeing data points to around 11 minutes of total cold immersion a week, split over several sessions.
- Contrast. Alternating hot and cold (sauna then plunge, 3–4 rounds) is widely used and barely studied; it is pleasant and probably harmless outside the contraindications below.
Who it suits — and who should avoid it
Cold suits people whose goal is feeling recovered and alert — endurance athletes between hard sessions, anyone in a competition week, people using it for mood. It does not suit people in a hypertrophy or strength block on training days, which is most of the people on a recomposition or lean-mass plan.
Do not, or ask a physician first
- Heart rhythm disorders, recent heart attack, uncontrolled hypertension. The cold-shock response is a large sympathetic surge; it has caused arrhythmias in people who did not know they had a problem.
- Raynaud's, cold urticaria, cold agglutinin disease, cryoglobulinaemia.
- Peripheral neuropathy, open wounds, pregnancy — relative.
- Never alone, never after alcohol. The gasp reflex and drowning are the real risk of open-water and bath immersion, not the cold itself.
- Whole-body cryotherapy with wet skin or without gloves — frostbite in minutes.
Where it fits in a personal protocol
The rule a coach applies is simple: no cold within four to six hours after a session meant to build muscle. On those days cold goes in the morning, before training, or not at all. On conditioning days, rest days and in deload weeks, a plunge is fine and often welcome. In a fat-loss phase the appetite and mood effects can help, but cold is not a calorie strategy and is written as a wellbeing lever, not a results lever.
Where a plan contains compounds studied for repair, cold is the one therapy that can work against them: the Wolverine combination and BPC-157 are studied for tissue repair that depends on blood flow and the inflammatory signal cold suppresses, so coaches keep immersion away from an acute injury in the first days. The lean-mass goal page and the sauna page cover the heat half of the contrast question — heat after lifting does not blunt adaptation, which is why sauna wins on training days.
The hype vs the evidence
- "Cold burns fat." Brown-fat activation is real and adds a few dozen calories a day. No trial has shown meaningful fat loss from cold alone.
- "Reduces inflammation." Acutely, in a muscle, yes. As a cure for systemic inflammation, no — and after lifting, that acute suppression is exactly what costs you muscle.
- "Colder and longer is stronger." The dose–response is unclear and the risk rises steeply below 10 °C. The trials used 10–15 °C.
- What is solid: less soreness, better perceived recovery for competition, a reliable mood lift, and a clear instruction to keep it away from hypertrophy sessions.
Frequently asked questions
How long after lifting is it safe to cold plunge?
Most coaches use four to six hours; the signalling studies measured suppression at two hours, and the twelve-week studies had people plunging immediately. Morning cold before an evening session is the cleanest arrangement.
Ice bath or cryo chamber?
The bath cools muscle and is what the soreness trials used. The chamber mostly cools skin and produces the hormonal and mood effect with less tissue effect. For recovery between competitions, water; for mood, either; for building muscle, neither on training days.
Does a cold shower count?
For the mood and immune findings, yes — the Dutch trial used 30–90-second cold showers. For deep muscle cooling it does not; that needs immersion.
Can I combine cold with a peptide research protocol?
Yes, with timing. Keep it away from hypertrophy sessions and from the first days of an acute injury where compounds studied for repair are in play. Your protocol marks the days.
What temperature should the water be?
The trials used 10–15 °C for 10–15 minutes. Below 10 °C the risk rises and the evidence thins; a bath you can tolerate for ten minutes is more useful than one you leave after two.
Want these built into a plan for you?
If cold belongs in your plan, the protocol says which days, how long and — more importantly — which days to keep it away from. €399, follow-up included.
Build my protocol Book a 15-minute call