Cold plunging—or immersing the majority of your body in literal ice water—is everywhere these days, and it’s not just athletes embracing the chill to ease post-workout muscle soreness. Scroll TikTok or Instagram long enough and you’ll inevitably see a fitness trainer, self-proclaimed biohacker, or celebrity slowly lowering their body into an ice water-filled tub while shivering and extolling the practice’s perks…often through gritted teeth.
But is it worth it? Does it get easier? And how, exactly, do you do it? Below, we highlight the existing research on cold plunging and whether it could boost workout recovery and performance, or elicit other physical and mental benefits. Plus, how you can try the trend and stay safe doing it.
What is a Cold Plunge?
A cold plunge simply refers to the act of immersing most of your body in cold water (typically between 50-60°F) for anywhere from one minute up to 10 minutes, depending on how acclimated you are to the cold. This can be done in various ways, from adding cold water and ice cubes to your bathtub or an outdoor trough or bucket to taking a dip in an icy lake.
Cold plunging has become increasingly popular: Google searches for cold plunge increased 14-fold from early 2022 to 2023, thanks in part to prominent plungers like Lizzo and Harry Styles spreading the trend on social media. But using cold water to reap health benefits is not new. Way before Dutch extreme athlete Wim Hof (“the iceman”) started setting cold exposure records and popularizing the practice, the ancient Greeks used cold water for therapeutic purposes, relaxation, and socialization; Hippocrates claimed it could reduce a lack of physical or mental energy; and even Thomas Jefferson used a cold foot bath every morning to maintain good health.
Cold water immersion (CWI) is a slightly more broad term that is often used in scientific research studies and may be used to describe a variety of cold water therapies, including cold plunges, cold water swimming, and cold showers. (You’ll see it mentioned throughout this article.)
Cold Plunge Benefits
So is taking the plunge really worth it? Research on cold plunge and cold water immersion benefits are far from conclusive (and many of the purported perks are anecdotal) but there is some promising preliminary data and proposed mechanisms worth highlighting. Just keep in mind: Cold plunging is considered a hormetic stressor that may be health-promoting in small doses—but too much could overtax your body, particularly if you’re already feeling burnt out. (More on how to cold plunge safely below).
Benefits (and Downsides) for Workout Recovery
It’s not uncommon for athletes to hop in an ice bath after a tough workout to help curb muscle soreness, inflammation, and swelling so they can get back to performing at their peak quickly (LeBron James does it, so it’s gotta be good, right?). But while a post-workout plunge may be supported in some contexts, it won’t necessarily support all of your fitness goals.
Let’s start with the positives: “There might be a benefit for muscle soreness in the short term that allows people to feel like they're getting back to their workouts more rapidly and or recovering better,” says exercise physiologist Alyssa Olenick, PhD, adding that cold plunging likely does this by curbing the body’s inflammatory and immune response to exercise. This might be particularly beneficial if you’re an athlete competing in back-to-back races or same-day training sessions—so you can blunt soreness and muscle fatigue, and optimize performance for your next bout of exercise.
Cold plunge benefits related to soreness, inflammation, and subsequent performance are supported, to an extent, by research. Below, we break down a quick overview on some of the most promising scientific literature:
In a small 2014 study, engaging in 10 minutes of cold water immersion at 50°F following high-intensity resistance exercise “enhanced recovery of submaximal muscle function.” Participants in the cold water group were able to lift more weight in muscle function tests compared to participants who had engaged in an active recovery method (low-intensity cycling). According to the study authors, these findings suggest cold water immersion could assist athletes who need to train or compete twice in the same day.
A 2012 Cochrane Review of 17 studies found some evidence that cold water immersion may reduce delayed-onset muscle soreness after exercise compared to passive recovery interventions such as rest. However, there wasn’t sufficient evidence to say cold water immersion was better than active recovery methods (e.g. walking, light cycling, foam rolling, massage, etc) or other methods like compression stockings.
A 2018 research review of 99 studies suggested that cold water immersion after strenuous exercise may reduce delayed onset muscle soreness, self-perceived feelings of fatigue, and inflammation—but only immersion in water lower than 59°F had a beneficial effect on inflammation.
A 2022 research review of 52 studies suggests that cold water immersion following high-intensity exercise has positive outcomes for muscular power, perceived recovery, and reduced muscle soreness (due in part to decreased circulating levels of creatine kinase, which is associated with muscle damage and soreness) 24 hours later. Shorter duration, lower temperature cold water immersion appeared to be the most effective.
However, if your goal is to build strength and increase muscle mass (and not just curb soreness in preparation for another imminent sweat session), there are some potential downsides to cold plunging after resistance/strength training specifically. The reason: “The same mechanisms by which cold water immersion curbs soreness and that feeling of post-workout fatigue also blunt the processes that contribute to muscle hypertrophy and strength.” (Muscle hypertrophy is when muscle protein synthesis exceeds muscle protein breakdown and results in muscle growth.)
In a small 2020 study, regular cold water immersion following resistance exercise reduced the expression of various genes and proteins involved in muscle hypertrophy; and in a 2021 review of eight studies, the regular use of cold water immersion had a negative impact on resistance training adaptations such as strength. According to Dr. Olenick, this doesn’t mean people who cold plunge right after resistance training will have no muscular adaptations, they will just be less compared to people who wait a few hours or don’t plunge at all. Fortunately, though, cold water immersion does not appear to negatively impact aerobic training adaptations or performance—so taking a plunge after a jog or indoor cycling session won’t be a problem.
A good strategy: Reserve cold plunges for cardio or rest days—and if you want to plunge on the same day as a resistance training session, experts like Andrew Huberman, PhD, recommend doing it beforehand or waiting at least four hours post-exercise so you don’t blunt your gains.
Other Potential Benefits of Cold Plunges
Cold plunging has the potential to support more than just workout recovery. According to Molly Maloof, MD, a physician specializing in personalized medicine and health optimization and author of The Spark Factor, various forms of cold exposure have the potential to support a healthy metabolism and immune system, improve stress resilience, boost mood, and more. Keep in mind: Findings from the studies below are not conclusive, but they do offer some potential explanations for cold water immersion’s many anecdotal benefits—AKA why it’s all over your TikTok feed.
Improved Mitochondrial Function
The process of adapting to the cold—as a result of regular cold plunges or other forms of cold exposure—appears to boost the number and activity of mitochondria in your cells, according to animal research. This is an example of hormesis—a process by which small amounts of stress generate a positive biological response. When done properly, hormetic stressors such as cold exposure “send signals to your mitochondria [which produce ATP] that they need to step up energy production to meet what might be an ongoing demand,” says Dr. Maloof. “The mitochondria comply, and you get more energy and greater capacity to handle stress, which translates to greater resilience.” Optimally functioning mitochondria may have beneficial downstream benefits on everything from mental health to longevity to immune function as well, she says.
Boosted Mental Health
A 2018 case study detailed the effects of regular cold water swimming on a 24-year-old woman with major depressive disorder and anxiety. After four months, she was able to manage her symptoms without medication. Of course, this was just one person, but some experts theorize that these benefits may be due to a release of feel-good neurochemicals such as beta-endorphins, dopamine and serotonin after cold exposure. Another theory: cross-adaptation—meaning, the biological adaptations you undergo when regularly exposed to one stressor (like a reduced inflammatory response after cold exposure) could improve your body’s response to another stressor and curb downstream symptoms, including psychological symptoms. Research also suggests that while cold exposure initially ramps up your sympathetic (fight-or-flight) stress response, acclimating to cold over time shifts you toward a more relaxed, parasympathetic state.
Cold water swimmers have reported that they suffer fewer and milder infections, which might be possible, since “short-term stress readies the body to deal with injury or infection,” according to a 2017 review on cold water immersion benefits and risks. Some studies have also found changes in the number and activity of innate and adaptive immune cells following cold water swimming and immersion, but changes were small and it’s not clear if it would result in reduced risk of illness.
Metabolism and Blood Sugar
Five-minute sessions of cold water immersion below 59°F have been associated with an increased metabolic rate—but it’s unclear if this contributes to significant health benefits or improvements in body composition or weight. Research on animals suggests that cold exposure stimulates brown adipose tissue (brown fat) to absorb glucose from the bloodstream faster, suggesting it may help maintain balanced blood sugar levels and insulin sensitivity, and a 2022 study on adults with overweight and obesity found that shivering during repeated exposure to cold decreased fasting blood sugar and blood lipid levels, among other findings.
The process of cooling and then rewarming after a plunge can act like a pump to boost blood circulation—which is important for clearing out waste and providing tissues with the oxygen and nutrition they need to function optimally. When you’re immersed in cold water, blood vessels in your extremities constrict and draw blood toward your core; but when you get out, your body warms, vessels expand or dilate, and blood is pushed back through the body. Some research suggests cold water immersion doesn’t just enhance circulation immediately post plunge, but that when done regularly, it may lead to microvascular adaptations that further enhance circulation over time.
How to Safely Add Cold Plunges to Your Routine
You should always get cleared by your doctor if you’re considering a cold plunge. Think twice about taking a plunge if you are experiencing high levels of stress, have a heart condition, take a heart-related medication, or have a circulatory problem such as Raynaud’s disease. And even if you’re cleared, make sure you always have a buddy with you.
Immersing your body in cold water, particularly when you’re not acclimated, comes with a host of potential risks—the quick drop in skin temperature can trigger a “cold shock” response in which you experience a rapid increase in breathing, heart rate, and blood pressure. This puts you at risk for drowning (if you unintentionally gasp when your head is submerged) and stresses the heart, which can increase your risk for a cardiac event, even cardiac arrest. The greatest risk for this cold shock response is within the first 30 seconds of cold water immersion, which is why you should never jump into an icy body of water or submerge your head right away. Hypothermia is also a risk, which typically sets in after 30 minutes in icy water in adults.
How to Cold Plunge: A Step-by-Step Guide
Once you’re ready, here are a few best practices tips to keep in mind:
Optimal cold plunge temperature
Aim for your water to be between 50 and 60°F if you’re new to cold plunges—in research studies, this temperature is typically low enough to elicit benefits.
Focus your breathing
Before slowly easing yourself into the water, center yourself with your breath so you don’t hyperventilate when you get in, suggests Dr. Maloof. You may choose to only submerge up to your waist if going neck deep is intimidating. Once in, slow your breathing so each breath takes about 3 seconds. (Do not hold your breath! This can increase risk of cardiac arrhythmias.)
How long to cold plunge?
To trigger the beneficial adaptations mentioned above, you need to stay in at least one minute and ideally 2-3 minutes, says Dr. Maloof. Don’t exceed 10 minutes at a time.
How often should you cold plunge?
Consider cold plunging a maximum of 1-2 times per week until you notice that your body is acclimating and cold immersion feels less stressful.
Finally, more cold plunging is not necessarily better. “You probably don’t need more than 11 minutes per week total of deliberate cold exposure,” says Dr. Maloof. “A lot of people try to go over this and do harm to their health,” she explains. “I had a patient who was doing long sauna sessions followed by 20-minute cold plunges. He developed major HPA axis dysfunction—a chronic stress condition that exhausts the adrenals and interferes with healthy cortisol output, causing many health issues, including chronic fatigue, depression, and frequent illness.”
How to DIY a Cold Plunge at Home
If you don’t have access to an ice bath at your gym or a nearby spa (this is still a rarity in most parts of the country), you can purchase a cold plunge tub, pod, or barrel for your deck or yard. You can also go the DIY route: If you live by a lake or cold body of water, you can do a cold plunge that way (as long as you can swim, of course). Some online cold plunge enthusiasts have created their own ice baths by adding water and bagged ice to a 100-gallon plastic stock tank. If you don’t have the outdoor space, you can also do this in your own bathtub.
Cold showers are great, too. While they may not have the same impact on muscle soreness and inflammation (since your body isn’t actually submerged in cold water), Dr. Maloof says they can help build your resilience to cold and boost levels of neurotransmitters like dopamine and norepinephrine, which support mood and alertness. “Work your way up to being in the shower for 2-3 minutes without turning it off. You get more bang for your buck if you let the cold water run on your face and neck,” which stimulates the vagus nerve.
Cold plunging is by no means a cure-all treatment and it comes with some risks if you don’t plan carefully. But preliminary research suggests that it may offer some benefits related to workout recovery (particularly post-workout soreness), and for overall physical and mental health when done correctly. Consider starting with cold showers and working up to 1-2 short cold plunges per week on non-strength training days — and always listen to your body.
This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.