The One About Cold Exposure and Ice Baths
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Katie: Hello and welcome to the Wellness Mama Podcast. I’m Katie from WellnessMama.com and this episode is a follow-up to the last short episode about sauna and heat exposure. And this one is all about cold exposure or cryotherapy or ice baths or cold plunges or whatever often called different areas.
This is part of a series of short solo episodes that will air in addition to the two regular interview episodes each week. I will try to keep these episodes short and under 30 minutes long, and I will cover my understanding of the research and any key points mentioned by guests in the last 600 plus episodes or in my own research. These are in response to requests of how to make these topics directly actionable without having to listen to dozens of episodes or delve into the research.
I’d also like to emphasize that these short episodes share my own understanding and experience with each of these topics, along with my key takeaways and summaries my Feynman summary, if you will. These, like all episodes, are for educational purposes only and should not be in any way considered medical or health advice. Like always, these are simply a starting point for your own research and experimentation. I encourage you to always do your own research, consult any necessary doctors or practitioners, and become your own primary healthcare provider. As I say often always question everything, including and especially me. Always stay curious and keep asking why.
All of that said, this one is all about cold exposure, ice baths, cryotherapy and the benefits, risk, minimum effective dose, and how to do it on a budget. Cold exposure, also known as cold therapy or cryotherapy, involves exposing the body to cold temperatures in some way to promote physical and mental health benefits. Ice baths are a specific form of cold exposure, where the individual immerses their body in a tub or pool filled with cold water of varying temperatures for a varying amount of time. Other forms of cold exposure include cold showers, ice packs, and even just spending time outdoors in cold weather. Cold exposure is believed to work by activating the body’s natural healing and adaptive processes, including the release of hormones and the activation of the immune system, among some other physiological processes that we’ll talk about.
Now, there are many reasons why someone may want to get cold exposure and incorporate cold therapy, but here are some of the most talked about online, at least. First being improved recovery and reduced inflammation along with boosted immune function, increased energy and alertness, improved circulation and cardiovascular health, reduced symptoms of depression and anxiety, potentially enhanced weight loss and metabolism, as well as anti-aging and skin health benefits. Overall, cold therapy or cold exposure is believed to potentially contribute to a wide range of physical and mental health benefits, including the ones I just mentioned. And it has become popular recently for people looking to optimize those specific things.
And I want to dive into some of the specific research associated with each of those. I’ll also say before jumping in, that I think cold exposure has its own set of benefits. I talked in the last episode all about sauna exposure and heat exposure and the many benefits there. I personally find sauna use to be even more beneficial than cold therapy. I think they can be used together and separately, which I will talk about more later for additional and separate benefits. But if I had to prioritize one, I think I personally would choose sauna, though many other people might choose cold plunge. And that’s simply my opinion. So let’s dive into some specifics.
Cold therapy has been shown to reduce inflammation by constricting blood vessels and decreasing blood flow to the affected area. This is why it can help reduce swelling, pain and inflammation by limiting the amount of fluid and immune cells that are able to enter the area. This is why it’s often recommended to put ice on an injury. Additionally, cold therapy can also help decrease the production of inflammatory cytokines, which are responsible for promoting inflammation in the body. There are some studies that support the use of cold therapy for inflammation, and this ranges from everything from putting ice on an injury all the way up to ice bath. There’s a 2015 study published in the Journal of Athletic Training that found that cold water immersion was effective for reducing inflammation and muscle soreness in athletes after intense exercise. A 2016 study published in the Journal of Strength and Conditioning Research found that cold water immersion was effective for reducing inflammation and improving muscle recovery.
And a 2019 study published in the Journal of Sports Medicine found that cold water immersion was effective for reducing inflammation and muscle damage in elite male soccer players. There’s also a 2020 study published in the Journal of Strength and Conditioning Research that found that cold water immersion was effective for reducing inflammation and muscle soreness.
Now, it is important to note that all of these studies were done in athletes or elite athletes. But overall, these studies suggest that cold therapy, particularly in the form of cold water immersion, can be an effective way to reduce inflammation and promote muscle recovery after exercise. Cold therapy is also believed to boost immune function by activating the body’s natural immune response, including increasing the production and activity of white blood cells. And there are some studies that support the use of cold therapy for boosting immune function as well, including one in 2016 in the Journal of Immunopathology and Pharmacology that found that whole body cryotherapy increased the activity of natural killer cells, which are important for immune function and fighting of infections.
2017 study published in the Journal of Human Sport and Exercise found that cold water immersion increased the production of white blood cells. While a 2018 study published in the European Journal of Applied Physiology found that cold water immersion increased the production of cytokines, which are important for regulating immune function. And a 2020 study found that cold water immersion increased the production of white blood cells and improved immune function in healthy individuals. And they did not look at specifically athletes in that one.
So overall, these studies suggest that cold therapy might have a positive impact on immune function, potentially reducing the risk of infections and other immune related conditions. However, I would say I wouldn’t put it at the top of my list from a strictly immune system perspective, I think the benefits, the stronger benefits, lie in other areas.
Cold therapy has also been shown to increase energy and improve mood, and I think this is one of the big points to talk about. It can activate the body’s stress response in a healthy way called hormesis, and it can increase the production of adrenaline and other hormones that can promote alertness and mental clarity. There’s some fascinating studies that really go into the energy and mood part of the equation, and like I said, I think this is one of the more compelling reasons..
So when it comes to energy and mood, a 2014 study published in the International Journal of Circumpolar Health found that cold water immersion improved cognitive function in mood in healthy individuals. A 2018 study in the Journal of Medical Investigation found that whole body cryotherapy improved mood and reduced symptoms of depression. They were looking at fibromyalgia patients. A 2019 study published in the International Journal of Sports Medicine found that cold water immersion improved mood and mental fatigue. And a 2020 study in the Journal of Affective Disorders found that cold water immersion improved mood and reduced symptoms of depression in patients with major depressive disorder.
If you have had the experience of getting into really cold water, especially up to your neck, you might have experienced a spontaneous laugh or giggle or kind of burst of both adrenaline and euphoria at the same time. And this is likely due to some of these things that these studies looked at. I think it’s, like I said, most compelling in this area. I use cold probably primarily for this reason myself and not actually for soreness and some of those things, which I will talk about why in a little while. But I do think the studies are pretty compelling that cold therapy can have a positive impact on energy levels and mood, especially reducing symptoms of fatigue and improving overall wellbeing.
There’s also some data that looks at cold therapy and cardiovascular health, and the theory here is that it’s increasing blood flow and promoting the health and function of blood vessels. Some of the studies that look into that include one in 2014 that showed that cold water immersion improved vascular function by increasing blood flow and promoting the production of nitric oxide, which is a compound that helps dilate blood vessels, and that often people might need to increase. A 2016 study published in the International Journal of Cardiology found that cold water immersion improved endothelial function, which is important for maintaining healthy blood vessels and reducing the risk of cardiovascular disease.
On the note of cardiovascular health, I also want to say I do think sauna has some more compelling evidence strictly for cardiovascular health. Personally, I like to use both and sometimes also them together, which is called contrast therapy. But there are studies that look at cardiovascular health from cold as well. A 2018 study published in the Journal of Applied Physiology found that cold water immersion improved blood flow and reduced inflammation in patients with peripheral artery disease. Sorry for the mispronunciations today, a condition that can lead to poor circulation and other cardiovascular problems. And lastly, a 2020 study from the European Journal of Applied Physiology that I mentioned before found that cold water immersion improved heart rate variability, which is a question I get often about how to improve that, which is and that is a measure of health and sort of the function of the autonomic nervous system. So if you are interested in improving HRV, there is some evidence that cold exposure may help.
Cold therapy has also been shown to improve metabolism. This is another reason many people are turning to it right now by increasing energy expenditure and promoting the activation of brown fat, which is the type of fat that is responsible for generating heat and burning calories. So while excess body fat has sort of a negative connotation, brown fat is a positive marker and one that many people are trying to increase in the body. Babies have a lot of brown fat naturally.
Some of the studies that look specifically at cold therapy in relation to metabolism include one in 2014 in the Journal of Clinical Investigation that showed that cold temperatures increased the activity of brown fat and improved insulin sensitivity in healthy people. A 2017 study, the Journal of Applied Physiology, found that cold water immersion increased energy expenditure and improved glucose metabolism, while a 2018 study found that cold water immersion increased the activity of brown fat and improved insulin activity in patients with type two diabetes. And a 2021 study published in the Journal of Obesity found that cold exposure through outdoor winter sports was associated with a lower risk of obesity and metabolic disorders in a large this was a large population based study.
Overall, I do think the evidence is pretty compelling that cold therapy, especially when done regularly, can have a positive impact on metabolism. By increasing energy expenditure, we can see it improving glucose metabolism and promoting the activation of brown fat. It does seem like this is somewhat dose dependent. It is wise to work up to higher amounts of cold exposure and that this is most effective when done over time.
Cold exposure has also been looked at in the aging equation and there’s no evidence that it can reduce aging by activating cellular processes that promote longevity and improve cellular health. Including this would be things like cold showers. Studies have looked at even just taking cold showers for several minutes each day and how this may actually start to activate brown fat and increased levels of adiposetan, which is a hormone that promotes cellular health and reduces inflammation. This can also potentially improve immune function, reduce the risk of some chronic diseases, and promote longevity.
One study in the journal Aging found that regular cold showers were associated with increased longevity and a lower risk of chronic diseases. There’s also something called whole body cryotherapy, which is exposing the body to extreme cold temperatures for several minutes at a time, usually from the air. And this also has been shown to activate cellular processes that promote longevity and improve cellular health. There’s a study in the journal Cryobiology that found that whole body cryotherapy improved antioxidant status and reduced oxidative stress in healthy individuals.
And then we have the now popularized ice baths or cold plunges that involve emerging the whole body in cold water for several minutes at a time. I personally find this one the most difficult, but also the most effective. And this has been shown to activate cellular processes that promote longevity, improve cellular health, including increasing levels of heat shock proteins. I know that sounds a little funny based on the name, but cold exposure can actually improve heat shock proteins and improve mitochondrial function. There’s another study here in the Journal Aging that found regular ice baths improved mitochondrial function and reduced inflammation in healthy individuals.
Cold therapy has also been shown to have mental and emotional benefits. I talked a little bit about the mood benefits before, but it also appears to be able to help with stress and anxiety and cognitive function. There are a lot of studies that look at this as well. There’s a study published in the Journal of Medical Hypotheses that found that cold water swimming was associated with improved mood and reduction in symptoms of depression and anxiety. And Dr. Andrew Huberman did a great podcast on this, which I would recommend and I will link to in the show notes. And he explained that cold exposure causes the prolonged release of dopamine, which is a powerful molecule capable of elevating mood enhancing focus and attention and goal oriented behavior and that even short bouts of cold exposure can cause a lasting increase in dopamine and a sustained elevation of mood, energy and focus.
Also, it appears that cold exposure, when done regularly, can reduce stress and anxiety by promoting the release of endorphins, which are natural mood boosting chemicals in the body. A study published in the Journal of Psychiatry Research found that whole body cryotherapy or ice baths reduce the symptoms of anxiety and depression, especially in patients with fibromyalgia. There’s also some studies that look at the enhanced cognitive function, which can help with improving focus and concentration. And a study published in the Journal of Pls One found that exposure to cold temperatures improved cognitive performance and healthy individuals.
There’s also of course the mental benefit and improved resilience which is often just from the act of having to get into the water and face that stress and adversity. But there was a study that found that repeated exposure to cold air or water improved the body’s ability physiologically to respond to stress as well.
So I, like I said, really like cold exposure for the mental and emotional and mood benefits the most. I do think it can also be very helpful with some of the other things we talked about including metabolism and cardiovascular health. And there’s also a wide range of ways that you can get this benefit all the way from things that are very low or no cost up to now very fancy solutions including cold plunges. So I just want to touch on these briefly.
You can start with anything as simple as cold showers, which is one of the easiest and most accessible ways to start to get the benefits of cold therapy. You can just start by turning the shower temperature down gradually until it’s as cold as possible and then spending even just 15 seconds in the cold water. And you can gradually increase that time each day until you can comfortably tolerate several minutes. One of my kids has transitioned entirely to only cold showers at this point. You can also, if you want to get some of the benefits and help cold adapt, is just put your face in a bowl of cold water, often with ice in it for up to 20-30 seconds at a time and do several rounds of that and that will actually help your body learn to adapt to cold. And I find that that’s great for the skin on the face.
You can also do something called whole body cryotherapy which is usually talking about exposing the body to extreme cold temperatures where the air is cooled anywhere down to negative 100 to negative 300 degrees Fahrenheit for several minutes at a time. This is usually done in specialized cryotherapy centers under the guidance of a trained professional. And I will say while I’ve enjoyed getting to try these in the past, I don’t find those more beneficial than ice baths and they tend to be pretty expensive and very difficult to actually do at home.
There’s also in health and wellness centers something called localized cryotherapy which involves applying cold therapy just to specific areas of the body using a device that delivers cold air or cold compress. This can also be done at home with a specialized device, but again, I prefer actually ice baths and notice bigger benefit there.
So on that note, ice baths and cold water swimming I would put at the top as personally what I find most beneficial. Ice baths involve immersion the whole the body in cold water for several minutes at a time. You can just have a bathtub with cold water and adding ice to reach the temperature I like somewhere in the high 40s or low 50s. You can begin by just doing a few seconds at a time or working up and eventually going up until now I will sometimes do three, four, five or even six minutes in high 40 or low 50 degree water. You can also do cold water swimming if that’s available to you, which involves, like it says, swimming in open water with temperatures ranging in that same 50 to 60 degree range, though I would say that is more dangerous. You never want to do that alone, always one with a partner and make sure that you are adapted for that. I find that cold just ice baths are more effective and more available than that.
Some general guidelines when it comes to cold exposure and as I said in the beginning, consult a practitioner, especially if you have a health condition, but always start slowly and gradually increase to cold temperatures to avoid injury or adverse effects. You don’t want to just jump in to a ten minute ice bathroom temperatures in the 30, as you will then cross the curve of good stress and probably cross into actual stress for your body. In general, it’s advised not to use cold therapy if you have a medical condition that affects circulation or if you are pregnant. And I always advise seeking guidance from a trained professional if you have any concerns whatsoever about using it safely.
But overall I think those are some of the ways that people can experience the benefits of cold, ranging from lower no cost like cold showers and dunking the face in a bowl of cold water all the way up to you can now buy a cold plunge that keeps the water clean and cold at all times. I will link in the show notes to the one I have from the Cold Plunge, which my kids and I use very often. But I don’t think you absolutely have to have a cold plunge to be able to get the benefits. You can do many of the same things in a bathtub or even just in a cold shower.
Like I said, what I started with was actually the ice on my face in a cold water, putting my face into a bowl of cold water. Then I did cold showers and then I’ve been through a progression of ice baths. We started with a metal cattle trough that we would add water and ice to on weekends. And now, because we’ve made that a habit in our house, we have the cold plunge which keeps the water clean and is much less work than getting bags of ice and dumping them in the cow trough. If you want to get the benefits of cold exposure, you might be interested in what the minimum effective dose is or how much you have to do to get the benefits.
And again, Andrew Huberman goes deep on this. There is some research that looks at this. But in general, the colder the water, the shower, the ice bath, whatever, the shorter the amount of time you need to expose yourself to it. So it’s kind of dose dependent and time dependent.
But one study showed significant and prolonged increases in dopamine when people were in cool water only about 60 degrees for about an hour or so up to their neck. That’s a long time. But other studies show increases with just 20 seconds in very cold water, 40 degrees or less. So the good news is that if you do deliberate cold exposure more often, you will be more comfortable in the cold and you can start to use colder temperatures with more confidence, just like with exercise, and you will need less time because you can go colder.
Huberman’s advice that has been very popular online and that I echo is to do deliberate cold exposure for eleven minutes per week. So not at a time, but total per week, which could be broken up into any number of sessions, ranging from a couple of minutes up and distributed across the week. You can do more, but that’s commonly agreed upon as the minimum effective dose. You can also do very cold, very brief exposures for adrenaline release, but the eleven minutes is based on a study that explores a range of effects and is considered kind of a basic starting point for general use.
Also you may be wondering about shivering, and there’s something called the Sober principle, which basically says that if we can enhance the metabolic effects of the cold by making our body reheat on its own after our cold exposure. So if mixing cold with sauna, this is one reason I like to end with cold, so that the body can have to reheat on its own. Some people also aim for going to the point of shivering as a metric of cold exposure, and this is a little bit controversial and debated, but it turns out that letting your body shiver may enhance metabolic increases. And one reason could be that shivering causes the release of succinate from the muscles, which might be helpful in activating brown fat thermogenesis so you don’t have to shiver, but it turns out that could be beneficial.
I also want to talk about for a minute sauna and cold together. So when combined in one session, heat exposure like sauna, and cold exposure like ice bath, this is called contrast therapy. I think this can also be beneficial, but I do like to think of contrast therapy as its own, a category of exposure, while also considering heat exposure alone and cold exposure alone. So in general I try to do all of those things in a given week. So some days I will just sauna, some days I will just get cold exposure and some days I will do both, which is called contrast therapy.
And a note on contrast therapy, it’s also called hot cold therapy and it involves alternating between periods of heat and cold exposure. And there are some benefits of this, specifically supported by research. One study showed it can reduce inflammation, which you may not want to do acutely after certain workouts. It can definitely promote circulation, because alternating between the heat and the cold can improve the delivery of oxygen and nutrients to the tissue. And there was a study that showed that this was effective in improving blood flow and oxygen saturation in the muscles. It can improve recovery. This contrast therapy can speed up recovery time and reduce muscle soreness after exercise. And some people find that it can enhance performance. Including a 2018 study published in the Journal of Sports Sciences found that contrast therapy improved jumping performance and reduced muscle fatigue in basketball players. So I consider that its own category.
And I also want to talk a little bit about cold exposure related to exercise. So it can be beneficial both before and after a workout, but with some caveat. There are some guidelines on when to do cold exposure related to exercise. Some studies suggest that cold exposure exposure before exercise can improve performance and reduce the risk of injury. This could include taking a cold shower, using an ice pack or a cold compress on the targeted muscle group, or performing a brief cold water immersion, such as a cold plunge. It can also be used after exercise, and you’ve perhaps seen this in a movie with athletes getting into an ice bath after their sport, and this can help reduce inflammation and promote recovery. This can also include anything from ice packs or cold compresses to a cold shower or longer cold water immersion in an ice bath.
However, there are some resources that show that cold exposure too soon after exercise can limit the strength or hypertrophy, meaning muscle growth benefits of the exercise. So I personally aim to do cold either before a workout or at least 4 to 6 hours, or the next day after a muscle or a workout where I’m trying to build either muscle size or strength. I also find that cold exposure is great on rest days, since it can help reduce inflammation. And it’s after that window when you want to let the body’s natural inflammation happen for muscle growth, and that can help shorten the recovery time as well.
Let’s also talk about when to do cold exposure. Again, there are many theories here. I personally like to do it earlier in the day. There are some resources that suggest that it might interfere with sleep when the body heats back up after cold exposure, if it’s done too late at night. I haven’t noticed that personally, but since cold exposure often tends to lead to a burst of energy focus and dopamine, I just find it more helpful earlier in the day and I aim for morning cold exposure.
And a last note about something called the thermal layer. If you get into cold water and you hold very still, you will eventually get it will get easier because you will create what’s called a thermal layer around your body of slightly warmer water. The antidote here, though not fun, is to move around or to be in moving water. And this is one of the reasons I like the cold plunge that I have, which I will link in the show notes because it moves the water the whole time. So it definitely feels tougher, but I find that it seems to get more benefit that way and the temperature is easily adjustable.
So if you want to try cold exposure and you have not before, if it were me and I was starting again, I would recommend starting with cold water in the face. Just dunking your face in a bowl of ice water, then progressing to cold showers and then eventually to something like a cold plunge or putting ice in your bathtub if that is a priority for you. Like always, I don’t think ice baths or cold plunges or any kind of expensive therapy are necessary for health. I think they can be a fun and helpful addition for those who it’s available to. And I think you can kind of split the difference and start to get the benefits at a lower no cost way by doing cold showers or submerging the base of ice water. And I will put some notes in the Show Notes at wellnessmama.fm with links to other podcasts that I have done with guests on cold exposure, to the blog post I’ve written on this and to the cold plunge that I have. If you’re interested in seeing that and I welcome any questions you have, please feel free always to leave those in the show notes at wellnessmama.fm or on YouTube or Instagram.
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