The Effects of Cold Water Immersion on Strength and Hypertrophy

Alan Fredendall // #FitnessAthleteFriday // www.ptonice.com

In today's episode of the PT on ICE Daily Show, Fitness Athlete division leader Alan Fredendall defines cold plunging, discusses the research behind cold plunging, and how to practically approach practicing cold plunging. Take a listen to learn how to discuss cold plunging with your patients or athletes.

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EPISODE TRANSCRIPTION

00:00 INTRO What's up everybody? Before we get rolling, I'd love to share a bit about Jane, the practice management software that we love and use here at ICE who are also our show sponsor. Jane knows that collecting new patient info, their consent, and signatures can be a time consuming process, but with their automated forms, it does not have to be. With Jane, you can assign intake forms to specific treatments or practitioners, and Jane takes care of sending the correct form out to your patients. Save even more time by requesting a credit card on file through your intake forms with the help of Jane Payments, their integrated PCI compliant payment solution. Conveniently, Jane will actually prompt your patients to fill out their intake form 24 hours before their appointment if they have not done so already. If you're looking to streamline your intake form collection, head over to jane.app slash physical therapy, book a one-on-one demo with a member of the Jane team. They'll be able to show you the features I just mentioned and answer any other questions you may have. Don't forget, if you do sign up, use the code ICEPT1MO for a one month grace period applied to your new account. Thanks everybody, enjoy the show.

01:25 ALAN FREDENDALL Alright, good morning PT on ICE Daily Show, happy Friday morning. Hope your morning is off to a great start. My name is Alan, I'm happy to be your host today. Currently, I have the pleasure of serving as a faculty member here in our fitness athlete division and the chief operating officer here at ICE. Fridays, our fitness athlete Fridays, we talk everything related to the recreational athlete, whether that's somebody in the gym doing CrossFit, powerlifting, Olympic weightlifting, bodybuilding, out on the track, the road, running, biking, swimming, whatever, that person who is getting after it. Four to six days per week is the focus here on fitness athlete Friday. We're biased, but we would argue it's the best darn day of the week. Courses coming your way from the fitness athlete division. Taking the summer off, we have some live courses coming up in September. You can catch Mitch Babcock out in Bismarck, North Dakota. That will be the weekend of September 9th and 10th, so the first September of the fall. And then you can catch Zach Long, aka the Barbell Physio out in Newark, California. That's the Bay Area. That's going to be the weekend of September 30th and October 1st. Online courses from us, our Essential Foundations, our eight week entry level online course starts back up September 11th. We're currently halfway through the current cohort. And then our Advanced Concepts course, our level two course that requires Essential Foundations, that drills down deep into things like Olympic weightlifting, gymnastics, programming, both for CrossFit and strength, injured athletes, all that sort of fun stuff. That starts September 17th. So you can find out more about our courses at ptenice.com. So today's topic, let's talk about cold plunging. You can't trip over a rock in public these days without finding somebody trying to get neck deep in some cold water somehow. Everybody's doing it. They're posting about it. There are probably a million ads you've seen on social media for this tub. This thing that looks like a bourbon barrel. This thing that looks like a fancy bathtub. All these different ways to essentially cool down your body. So I want to attack this topic from three different angles. I want to talk about defining a cold plunge and how probably most of the people cold plunging currently or certainly what we see happen on the Internet is not true cold plunging. I want to talk about the research supporting, not supporting the use of cold plunging. And I want to talk about the practical application of what we can recommend to our patients and athletes when they come into the clinic or the gym and ask us what we know about cold plunging. What's the best way to cold plunging and all that sort of thing. So let's start from the beginning. What is a cold plunge? We need to start at the top and understand that humans have a really large tolerance for heat at rest and a very poor tolerance for cold at rest. You can imagine it's much better to sit outside on a 90 degree day than a 30 degree day. So our perception of temperature is a little bit different. It's skewed based on if we're active or if we're resting. It flips entirely when we are active. You can imagine how terrible it would be to run on a 100 degree day versus running on maybe a 50 degree day. We would all probably much choose the 50 degree day because our bodies lose heat tolerance as our activity level increases, which is all that to say of we have a really poor tolerance for cold at rest, which means when we define the parameters of what's used for cold plunging in research, we'll quickly recognize that most of us, most of the people we see aren't doing it cold enough. They aren't doing it long enough and they aren't exposing as much of their body as they need to to the cold plunge. So a cold plunge is defined by the research is going to be exposure up to your neck or possibly your entire body for 10 minutes at 40 to 50 degrees Fahrenheit. That's a large portion of our body. That's a really long duration of cold exposure for a human being at rest. And that is relatively cold. Again, we have a really poor tolerance to cold at rest. Now, imagine we've we've all taken a bath. Imagine you you take a hot bath or sit in a bathtub and then you get that feeling of, oh, I'm getting really cold. Like this water has cooled down significantly. Again, our perception of temperature is really skewed. When we decide it's time to get out of the bath because the bath water has become too cold, we've probably started in bath water of maybe one hundred and five to one hundred and ten degrees. And it has only cooled down to maybe 90 to 95 to the point where we say this is cold, quote unquote, cold. I'm going to get out of the bathtub now. But really, 90 to 95 degree water is remarkably warm compared to what we define as cold plunge in the literature. So most folks are probably simply not getting their water cold enough to even define cold plunging. Again, the duration of support in the research is cold plunging of 10 minutes. So if you are doing it for 30 seconds or one minute, just know you are not anywhere close to reaping the effects or the positive or negative that we've seen in the research. If you're only dipping your toe in for a few minutes or jumping in up to your knees or your waist and hopping back out again in the research, exposure would define itself as being exposed up to the neck, at least. So many folks just putting their legs in a cold plunge, just going up to the level of maybe the knee, going up to maybe the level of the waist or maybe belly button mid chest or something. Again, if you're doing that to slowly gain tolerance, that's OK. But if that's what you're calling normal cold plunging, just know you're probably not reaping as much of the effect. Again, positive or negative that we'll talk about here in a second as you could be. So cold plunging 40 to 50 degrees up to your neck, duration of about 10 minutes. So all that to say, most people are probably not actually cold plunging when we do it ourselves or we watch others do it. Excuse me. Simply not cold enough, not enough for their body to get in effect and not enough for a long duration. I do want to give a special shout out to ICE faculty members Dustin Jones and Jeff Musgrave. They are unashamedly posting their cold plunges every day on social media and they really get after it. You can see that they have a bunch of ICE in their backyard cold plunges and they're sometimes exposing their whole body to the cold plunges. So they are doing it right. That's the way to do it. So let's switch gears and talk about what does the research say. The research in this field is becoming overwhelming of just looking at the trend and volume of research. Eight hundred and seventy articles published on what the research would call cold water immersion since 2008. So an exponential growth in the people studying, the amount of people studying and the volume of research studying this particular area of what we might call athletic recovery. I want to talk about just two journals today, two journal articles. There are literally like we talked about hundreds and hundreds and hundreds and hundreds. But I really want to talk about two. What I like about these two articles I want to share is that they are 30 years apart and they essentially say the same thing. So first, I want to go way back. 1985, I wasn't even alive yet. Journal of Applied Physiology, Peterson and colleagues talking about cold plunging exposure after exercise. These folks did three sessions a week of what the again the research calls cold water immersion or cold plunging. They did do it at 50 degrees Fahrenheit. They did it for 15 minutes instead of 10. So they went up to their neck. They did it for 15 minutes and they did it cold enough. 50 degrees Fahrenheit. They did this three times a week after resistance training. Evaluation here looked at a lot of different things. One rep max leg press, one rep max bench press and some ballistic things, counter movement, jump, squat, jump, ballistic push up. And this article really wanted to focus on what happens to muscular hypertrophy. This journal article, 1985, now 38 years ago, said you can expect to have less muscular hypertrophy if you expose yourself to a cold plunge after resistance exercise as compared to control. Control in this group was people who just sat at room temperature like you might sit on the boxes at CrossFit class or on the curb after a really long hard run. They just sat and kind of cooled down for 15 minutes compared to the cold plunge group. Fast forward 30 years, 2015, Journal of Physiology, Peking Colleagues, very similar parameters. That's why I picked these two papers. They are perfectly 30 years apart. They use almost exactly the same parameters and they found pretty much the same thing. Peking Colleagues in 2015, very similar parameters, twice a week of cold plunge exposure, 10 minutes at a time, also 50 degrees Fahrenheit. They followed folks a little bit longer. Peter Peterson in 1985 followed those athletes for seven weeks. Peak in 2015 followed them for 12 weeks. Almost same exact parameters, though. They looked at almost exactly the same stuff. They looked at leg press strength, knee extension strength, knee flexion strength, both one rep max and eight rep max. So they're looking at maximal strength and they're also beginning to look at kind of what is your ability to produce force over time. So what we call maybe endurance, which really is indicative of hypertrophy. This team also did some muscle biopsies and what they found with the group exposing themselves to the cold plunge after resistance training compared to the control group, in this case, a group doing active recovery. So not even resting, just doing active recovery for 10 minutes after the resistance training session. The control group, who continued to exercise at a low level, had a 17% improvement in hypertrophy, a 19% improvement in isokinetic strength and a 26% improvement in myonuclei per muscle fiber. So the control group blew the cold plunge group out of the water. Now, that is not to say that the cold plunge group got weaker or smaller. They did not get as strong and big as the control group. And it's led to believe because they were the cold water immersion group, that it's the cold plunge, that something about that cold exposure seems to blunt the body's natural response for healing to encourage hypertrophy gains and strength gains. The big takeaway from this study is the myonuclei per muscle fiber. We can think of myonuclei as if one myonuclei per muscle fiber is great, but more is better. It's almost like having a personal assistant for everything in your life. Your life would be a lot easier if you woke up in the morning and someone was there who had your clothes ready for you. If someone was there who had already prepped your shower for you, if someone was there who already made your breakfast for you, right? The more people you have assisting you in your life, the more efficient you will be at running your life because they're doing everything for you. That's a lot of the role of the myonuclei in our muscles. The more the better. The interesting thing about myonuclei is they stick around even during a period of training, whether it's injury, whether we get busy with life, whether we switch training modalities, maybe we start prioritizing endurance training to train for a marathon or something. Those myonuclei stay around and that's kind of what creates that strength across life of that person who comes into the gym who says, I haven't worked out in 10 years and then deadlifts 400 pounds. You're like, where did that come from? That took me years to build to that strength. This person just naturally has it. Yes, they may naturally have some genetic strength, but what they probably had in the past from training was myonuclei that are now living in their body. And so losing those myonuclei or rather not gaining them through cold plunge exposure not only affects strength and hypertrophy in the short term, but affects really long term fitness gains over time. So very interesting study from PEEK and colleagues showing that cold water immersion after resistance training seems to really have a negative effect on strength and hypertrophy. So it doesn't seem to help. It maybe seems to have a negative benefit, at least after resistance training. Most people aren't doing it correctly. What is the actual practical application? What can we recommend to patients and athletes who ask us about cold plunging? The first thing is to make sure that they understand what it actually is and that they're doing it correctly. Of, hey, if you're going to do this, you should have a way to expose yourself up to the neck, your whole body up to your neck. You should build up your tolerance to do it in sessions of 10 minutes at a time. And the water should be really uncomfortably cold, 40 to 50 degrees Fahrenheit. We don't like to see colder than that. That can be a little bit dangerous, but we also don't like to see warmer than that. Right. Remember, cold bath water is technically hot, 90 degrees Fahrenheit. So we need to see somewhere between 40 to 50 degrees Fahrenheit. We need to talk about timing of cold plunging. The research would really suggest we should never do it after training, especially if we're just training once a day. We're training for life. We're training to be strong and be training for life. And we're not training to be competitive athletes. We're not training multiple times per day. If you're somebody that just exercises once a day, you should not finish that exercise session with a cold plunge. Maybe you start your day with a cold plunge or maybe you cold plunge before you exercise to get the effects that cold plunging can have aside from apparently blunting our strength and hypertrophy gains. And then there's a little bit of a caveat there for competitive athletes, folks who are, you know, let's think of a CrossFit Games athlete. Let's think of somebody running multiple races, an Ironman, a long cycle race. Maybe between events is the time for a cold plunge. We need to recognize those events are already really destructive to the body. Nobody goes to the CrossFit Games and comes away fitter. They come away significantly beat up with probably weeks or maybe even months of repair time needed to recover from an event like that. So at that event, we're not as concerned about not gaining as much strength and hypertrophy as possible because of the short duration. It's only a couple of days or maybe even a one day competition is only a couple of hours. So maybe that is the time between events to use cold plunging. But after regular training, we should not use it. We need to recognize the point of exercise is to create a micro injury that your body will repair and heal from. Your tissues get stronger from a tensile strength perspective and your brain more effectively learns how to use those muscles so that we get stronger and bigger over time. We become more adapted to the stress. We have an increase in tensile strength. We have an increase in myonuclide per muscle fiber. And that's what really creates robust lifelong strength. I love the quote from Pique and colleagues. Remember that anything intended to mitigate and improve the body's natural ability to improve resilience to physiological stress with exercise may actually be counterproductive to muscular adaptation. Cold plunging, NSAIDs, antioxidants, anything that can slow the chemical reactions, the natural chemical reactions in our body to respond to that micro injury is going to affect our ability to recover and be more resilient to that stressor in the future. So a lot like discouraging folks from taking a bunch of maybe ibuprofen or injectable steroids, we should say, hey, if you're going to cold plunge, make sure you start your day with it. Make sure you do it before training. You should really try to avoid finishing that workout and jumping right out into that maybe that cold plunge in the in the gym parking lot, because this research is really so profound of you're leaving maybe 20% improvement in strength and hypertrophy on the table when you cold plunge after training if you don't. So cold plunging, what is it? How does it work? Does it have a negative effect? Yes, it seems to. But also, that doesn't mean that we should say just don't do it. If you enjoy it, if it helps you start your day, if it helps you feel less sore, by all means, cold plunge. But let's rearrange when you cold plunge in your day to make sure that we're not doing it after training. And let's make sure we're doing it correctly up to our neck in the water, cold water, 40 to 50 degrees Fahrenheit. And duration should be at least 10 minutes, right? If you're just up to your knees in 60 degree water for two minutes, you're not actually cold plunging. You should feel good. You're probably not going to get a negative effect from that because you're not doing it correctly. But you're also leaving a lot on the table by not doing it correctly. So cold plunging. Hope this was helpful. We just revamped week five of our Central Foundations course to include a whole bunch of different training modalities like cold plunging. We talk about hot tubs now. We talk about saunas, both infrared and traditional saunas. We talk about compression therapy, massage, pneumatic boots, massage guns, everything folks have a question about. So if you've already taken the Central Foundations, head on over, check out week five for that update. If you haven't taken it yet, remember, September 11th is your next chance. So have a fantastic weekend. I hope you all have a lovely long four day weekend for 4th of July. We'll see everybody next time. Bye everybody.

18:00 OUTROHey, thanks for tuning in to the PT on Ice Daily Show. If you enjoyed this content, head on over to iTunes and leave us a review and be sure to check us out on Facebook and Instagram at the Institute of Clinical Excellence. If you're interested in getting plugged into more ice content on a weekly basis while earning CU's from home, check out our virtual ice online mentorship program at PT on ice dot com. While you're there, sign up for our hump day hustling newsletter for a free email every Wednesday morning with our top five research articles and social media posts that we think are worth reading. Head over to PT on ice dot com and scroll to the bottom of the page to sign up.