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Cold plunge benefits: what the science actually says
Cold plunges and ice baths are credited with everything from faster recovery to fat loss and a stronger immune system. Some of that is backed by good research. A lot of it isn't. Here's each claimed benefit, what the studies actually found, and how strong the evidence is.
General information, not medical advice. For an injury, or pain that is severe or not improving, see a doctor or physiotherapist.
The best-supported benefits of cold plunging are less muscle soreness after hard exercise[1] and fast whole-body cooling after exercise in the heat.[2] Many people also feel more alert and upbeat afterwards,[3] and early research links regular cold exposure to brown fat activity and better insulin sensitivity.[4][5] Claims about weight loss, immunity and faster injury healing are weak or unproven.[5][6] And used straight after every strength session, cold plunges may reduce muscle gains.[7]
What is a cold plunge?
A cold plunge is sitting in cold water up to your chest or neck for a few minutes. An ice bath is the same idea, with ice added to a tub of water. A cold plunge usually means a dedicated tub with a chiller that keeps the water cold without ice. Your body doesn't care which one you use. It's the cold water that counts.
Researchers call both cold water immersion (CWI). Studies vary widely in water temperature, duration, how much of the body is submerged, and whether participants are experienced cold-water swimmers, which is one reason results are hard to compare.
Every claimed benefit, rated
1. Less muscle soreness after hard exercise
The most reliable benefit. People who sit in cold water after a hard session usually report feeling less sore over the following days than people who just rest.
A Cochrane review found cold water immersion reduced muscle soreness ratings at 24, 48, 72 and 96 hours after exercise compared with passive rest. The authors rated the evidence quality as low because many trials were small, but the direction of effect was consistent.[1] A 2016 meta-analysis found the best results with water at about 10–15 °C for 10–15 minutes.[9]
2. Fast cooling after exercise in the heat
If you're overheated after training in hot conditions, water is far better at pulling heat out of the whole body than air. That's a real, physical benefit of full-body immersion.
Water conducts heat far better than air, so immersion cools the body quickly. Cold water immersion is also the standard emergency treatment for exertional heat stroke, a medical emergency rather than recovery. A 2017 review in Experimental Physiology covers cold water immersion both as a hazard and as a treatment for overheated casualties.[2]
3. Feeling more alert and in a better mood
Most people get out of a cold plunge buzzing. That rush is real: cold triggers a big release of the body's alertness chemicals.
In a 2000 study, young men immersed to the neck in 14 °C water had a 530% rise in noradrenaline and a 250% rise in dopamine, and their metabolic rate rose by 350%. That immersion lasted an hour, far longer than a typical plunge, so effects from a few minutes are likely smaller.[3] Studies on longer-term mood benefits are limited.[5]
4. Brown fat and metabolism
Your body has a small amount of brown fat that burns energy to make heat. Cold switches it on. Early research suggests regular cold exposure might help how the body handles blood sugar, but it's not a shortcut to weight loss.
A 2009 New England Journal of Medicine study detected cold-activated brown adipose tissue in 23 of 24 healthy men during mild cold exposure (16 °C air), with lower activity in men who were overweight.[4] A 2022 review of 104 studies found cold water immersion seems to reduce or transform body fat tissue and improve insulin sensitivity, but noted most studies were small.[5]
5. Fewer sick days
One large trial found people who ended their showers cold took fewer sick days off work, but they didn't actually get ill less often. They may simply have felt well enough to go in.
In a randomised trial of 3,018 adults, a daily (hot-to-) cold shower for 30–90 seconds led to a 29% reduction in self-reported sickness absence from work, but no significant difference in the number of illness days. This was cold showers, not plunges.[6]
6. Weight loss
There's no good evidence that cold plunging causes meaningful fat loss. Cold does raise energy use while you're in it[3] and it activates brown fat,[4] but the effect on body weight over time hasn't been shown in quality trials.[5]
7. Faster injury healing
Uncertain. Cold eases pain, but whether it speeds tissue healing is unproven,[10] and newer injury guidance (PEACE & LOVE) doesn't include ice at all.[8] More on RICE and what has changed →
8. Bigger strength or muscle gains: the opposite
A 2015 study found that regular cold water immersion straight after strength training reduced long-term gains in muscle mass and strength.[7] If size and strength are your goals, plunge on other days, or after endurance or skill sessions, not right after lifting.
The downsides
- Cold shock: an involuntary gasp and a surge in heart rate and blood pressure in the first minutes.[2]
- Hypothermia if you stay in too long, with body temperature that can keep falling after you get out.[2]
- Shared tubs in teams and gyms can spread skin infections.[11][12]
- Cost and hassle: ice every time, or a chilled plunge tub, plus space and cleaning.
Read the full list of ice bath downsides →
How to cold plunge safely
- Check with a doctor first if you have a heart condition, high blood pressure, Raynaud's, a cold allergy (cold urticaria), or are pregnant.
- Never plunge alone, and keep your head above the water.
- Get in slowly and focus on slow breathing through the first minute.
- Start short and not too cold. For post-exercise soreness, a meta-analysis found the best results at about 10–15 °C (50–59 °F) for 10–15 minutes.[9] Many people start with a minute or two and build up.
- Get out if you shiver uncontrollably, feel dizzy or feel unwell.
- Warm up gradually afterwards with dry clothes and movement. Avoid an immediate very hot shower.
When a cooling wrap makes more sense
To be clear: a cooling wrap won't give you the whole-body rush or the brown fat effect of a plunge. Those need your whole body in cold water. But if what you actually want is a sore knee, shoulder or back to feel better after training, you don't need to put your whole body through the cold to get it.
Recoolvery+ is not an ice pack and not a plunge. It's a cooling recovery wrap: freezable HypoCarbon® pads (35.0 W/m·K in in-house testing, against 2.3 for ice) held on the area that needs it by three straps. No cold shock, no shared water, no ice to buy, and you can move around while you cool.[13][14]
See the Recoolvery+ Wrap → · How cooling works on the body →
Questions
What are the benefits of a cold plunge?
The best-supported benefits are reduced muscle soreness after hard exercise and fast whole-body cooling after exercise in the heat. Many people also feel more alert afterwards, and early research links regular cold exposure to brown fat activity and better insulin sensitivity. Evidence for weight loss, immunity and faster injury healing is weak.
Is cold plunging good for you?
For healthy people who do it safely, it can help with post-exercise soreness and many find it energising. It also carries risks, such as cold shock and hypothermia, and isn't suitable for everyone. Check with a doctor first if you have a heart condition or high blood pressure.
How long should you cold plunge?
Post-exercise recovery studies commonly use about 10 to 15 minutes in water around 10 to 15 °C (50 to 59 °F). Many people start with one or two minutes and build up. Never plunge alone, and get out if you shiver uncontrollably or feel unwell.
Does cold plunging help you lose weight?
There's no good evidence that it leads to meaningful fat loss. Cold raises energy use temporarily and activates brown fat, but long-term effects on body weight haven't been shown.
Should I cold plunge after lifting weights?
Not routinely if muscle growth is your goal. A 2015 study found regular cold water immersion straight after strength training reduced long-term gains in muscle mass and strength. Plunge on other days or after endurance sessions instead.
What's the difference between an ice bath and a cold plunge?
Both mean immersing your body in cold water. An ice bath uses ice to chill the water; a cold plunge usually means a dedicated tub with a chiller. The effects on the body are the same.
References
- Bleakley C, McDonough S, Gardner E, et al. Cold-water immersion (cryotherapy) for preventing and treating muscle soreness after exercise. Cochrane Database of Systematic Reviews, 2012. doi.org/10.1002/14651858.CD008262.pub2
- Tipton MJ, Collier N, Massey H, Corbett J, Harper M. Cold water immersion: kill or cure? Experimental Physiology, 2017. doi.org/10.1113/EP086283
- Šrámek P, Šimečková M, Janský L, et al. Human physiological responses to immersion into water of different temperatures. European Journal of Applied Physiology, 2000. doi.org/10.1007/s004210050065
- van Marken Lichtenbelt WD, Vanhommerig JW, Smulders NM, et al. Cold-activated brown adipose tissue in healthy men. New England Journal of Medicine, 2009. doi.org/10.1056/NEJMoa0808718
- Esperland D, de Weerd L, Mercer JB. Health effects of voluntary exposure to cold water: a continuing subject of debate. International Journal of Circumpolar Health, 2022. doi.org/10.1080/22423982.2022.2111789
- Buijze GA, Sierevelt IN, van der Heijden BC, et al. The effect of cold showering on health and work: a randomized controlled trial. PLoS One, 2016. doi.org/10.1371/journal.pone.0161749
- Roberts LA, Raastad T, Markworth JF, et al. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. Journal of Physiology, 2015. doi.org/10.1113/JP270570
- Dubois B, Esculier JF. Soft-tissue injuries simply need PEACE and LOVE. British Journal of Sports Medicine, 2019 (print 2020). doi.org/10.1136/bjsports-2019-101253
- Machado AF, Ferreira PH, Micheletti JK, et al. Can water temperature and immersion time influence the effect of cold water immersion on muscle soreness? A systematic review and meta-analysis. Sports Medicine, 2016. doi.org/10.1007/s40279-015-0431-7
- Malanga GA, Yan N, Stark J. Mechanisms and efficacy of heat and cold therapies for musculoskeletal injury. Postgraduate Medicine, 2015. doi.org/10.1080/00325481.2015.992719
- Begier EM, Frenette K, Barrett NL, et al. A high-morbidity outbreak of methicillin-resistant Staphylococcus aureus among players on a college football team, facilitated by cosmetic body shaving and turf burns. Clinical Infectious Diseases, 2004. doi.org/10.1086/425313
- Kahanov L, Kim YK, Eberman L, et al. Staphylococcus aureus and community-associated MRSA in and around therapeutic whirlpools in college athletic training rooms. Journal of Athletic Training, 2015. doi.org/10.4085/1062-6050-49.3.96
- HypoCarbon® thermal conductivity (35.0 W/m·K): Global Healthcare SG in-house testing of the proprietary formulation. Unpublished company data, available to clinical and trade partners on request.
- Slack GA. Thermal conductivity of ice. Physical Review B, 1980. doi.org/10.1103/PhysRevB.22.3065
Recoolvery+
Cooling for your recovery routine
Not an ice pack. Freezable HypoCarbon® pads in a hands-free wrap for the knee, shoulder, elbow, ankle and back. HypoCarbon® conducts heat 15× better than ice. Cold only, no heating.
See the Recoolvery+ Wrap