An ice bath is a form of cryotherapy in which an individual submerges their body in an ice-cold bath for a short period. Also called cold-water immersion, an ice bath is a form of passive-active recovery that may potentially ease muscle pain and reduce inflammation by boosting blood flow.
Cooling your body after a workout delivers much-needed oxygen and nutrients to the muscles, which need help to recover after a hard workout. Cold water immersion is also known to help restore heart rate after intense workouts.
Ice baths activate two hormones – Irisin and FGF21 – that help to burn your body fats.
Cold water also stimulates the tiny muscles in your skin pores to give you tighter, firmer, more youthful skin.
Evidence shows that could therapy prolongs the lifespan by 10% to 21%.
Originally, ice baths were a common part of athletes' training and recovery regimen, but ice baths could have more benefits in your wellness routine.
What does an ice bath do for your body?
First, an ice bath activates “cold shock proteins” in your body. These proteins can protect our cells from unfavorable conditions and adapt to them. Secondly, the ice bath and the compression from the water pressure cause constriction of blood vessels, which could have a positive effect on the organism. So what are the scientific-based benefits of ice baths for your body?
What are the benefits of an ice bath?
Cold baths are effective after workouts
After an intense workout, there is some microtrauma and tears in the muscle fibers. This muscle damage stimulates muscle cell activity and helps in the repair and strengthening of the muscle. Cooling your body after a workout reduces nerve impulse transmission and thus reduces the level of pain perception and induces constriction of blood vessels in peripheral tissues (e.g., muscle) which results in reducing exercise-induced acute inflammation. This also delivers much-needed oxygen and nutrients to the muscles, which in theory should help them to recover after a hard workout. Cold water immersion is also known to help restore heart rate after intense workouts. Interestingly, there is evidence that suggests that cooling the exercised muscle increases the cellular signal which turns on mitochondrial biogenesis. During this biogenesis, mitochondria amplify and produce more energy in the cells. This lets muscles recover faster.
Cold baths could help with weight loss
Scientific research showed that ice baths could activate two hormones, irisin, and FGF21, which are detected in our brown fat (brown fat is a metabolically active “good guy” and can burn our white “belly” fat). These two “fat loss” hormones are produced only when our muscles are shivering. Specifically, 10–15 minutes of shivering increases irisin to such a level that it has the same effect as an hour of moderate exercise. According to longevity expert and Harvard geneticist David Sinclair, Ph.D., brown fat burns energy to create heat and manage body temperature, which is why it's activated by colder temperatures. This process might lead to weight loss.
Your skin will thank you for cold baths
In contrast with hot water, cold baths can soothe itchy, irritated skin, as the cold water does not dissolve away natural skin oils. Cold water also stimulates the tiny muscles in your skin pores to give you tighter, firmer, more youthful skin. It is also known that cold temperatures can constrict the blood vessels in the skin, which can reduce swelling and inflammation. Tightening pores with cold water can also temporarily help to reduce any ingress of pollutants and thus improve the skin's ability to function and respond to free radicals or fight cellular injury.
Ice baths can affect your brain – a benefit for your mental health
Ice baths activate the sympathetic nervous system – blood vessels constrict and the vagus nerve is stimulated, causing a cascade of positive effects. The release of hormones norepinephrine and adrenaline from taking an ice bath could have some effect on the brain that shows great promise for alternatives to prescription medications. In one study, the cold shock was shown to significantly increase the production of the hormone and neurotransmitter norepinephrine in the brain, which significantly impacts mood and energy. The evidence shows the norepinephrine boost from a cold plunge session of just 2 minutes could also boost mood. In another study, the cortisol (stress hormone) levels of participants who took cold showers decreased significantly, showing that cold exposure can reduce hormones related to stress and poor mood. A 1-hour immersion in 57°F (14°C) water decreased cortisol levels in healthy individuals.
Longevity and ice baths – more knowledge is needed
Studies with exposure to the cold are done with mice, rats, fruit flies, and worms. Evidence shows that cold therapy prolongs the lifespan by 10–21%. So it is well-established across multiple organisms that a low basal body temperature results in increased longevity within a species. It is also known that cold therapy may impart longevity benefits through the mTOR pathway in a cell-specific manner and stimulate several longevity-associated molecules: adiponectin, SIRT1, FGF-21, and irisin. A recent review concluded with promising, but inconclusive evidence, that whole-body ice baths reduce inflammation and/or improve immune function in humans. After controlling for multiple confounding variables, a study in Belgium found telomere length to have been increased prenatally in fetuses gestated in colder environments.
What are the risks of an ice bath?
Generally, ice baths are not dangerous. But they are not recommended for people with certain conditions:
- Circulatory issues like peripheral vascular disease.
- A history of frostbite.
- Raynaud's disease, which involves sensitivity to cold.
- An open wound or recent surgery.
How to make an ice bath? Tips and recommendations
Fill a tub with cold water. Fill a tub halfway with cold water and ice. One to three bags of ice should be enough to achieve the optimal water temperature—between 53–64°F (12–18°C)—depending on your cold tolerance level.
Stage your post-bath clothing. After your ice bath, you’ll need to dry off and get into warm clothes to bring your body temperature up. Stage your post-bath clothes in the bathroom before you enter the bath so you can access them quickly.
Set an alarm (optional). You can set an alarm on your phone to ensure that you do not stay in the ice bath for longer than 15 minutes, which is the maximum recommended length of time for this form of cryotherapy. The optimal timing is 10–12 minutes.
Enter the ice bath. Slowly submerge your feet, legs, and waist into the ice bath. Entering the water too quickly can shock your system, so it’s best to ease in slowly. As you enter, breathe deeply to stay calm. The parts of your body submerged in the water will start to feel numb after a few minutes.
Soak in the ice bath for up to 15 minutes (optimal 10–12 minutes). Once you’ve adjusted to the water, briefly submerge parts of your upper body. Consider meditating to take your mind off the extreme temperature drop.
Get out and warm up. Exit the bath slowly. Next, use a towel to dry off and put on the warm, dry layers that you staged nearby. Warm up faster by drinking a warm beverage.
- NIH. Chronic cold exposure increases RGS7 expression and decreases alpha(2)-autoreceptor-mediated inhibition of noradrenergic locus coeruleus neurons.
- NIH. Scientific Evidence-Based Effects of Hydrotherapy on Various Systems of the Body.
- NIH. Human physiological responses to immersion into water of different temperatures.
- NIH. Eukaryotic response to hypothermia in relation to integrated stress responses.
- NIH. The cAMP/PKA pathway rapidly activates SIRT1 to promote fatty acid oxidation independently of changes in NAD(+).
- NIH. Early Biological Aging and Fetal Exposure to High and Low Ambient Temperature: A Birth Cohort Study.