At this point, it's nearly impossible to have neither heard of nor seen someone you know plunging into a trough filled with water and ice for several minutes at a time, then jumping out, bright red, proclaiming the myriad benefits they're set to gain from those long, slow, painful minutes spent freezing their marbles off. It's really fascinating how certain things in the health and fitness realm skyrocket in popularity while others don't. While I lack concrete evidence, my guess is that this phenomenon is tied to our collective yearning for quick fixes to our less-than-ideal lifestyles. Overhauling a lifestyle that's completely out of sync can seem like a monumental, daunting task, involving a multitude of factors: sufficient aerobic and resistance exercise, deep and REM sleep, adequate intake of water, protein, fiber, omega-3 fatty acids, micronutrients, daily steps, and the list goes on.

The appeal of the quick, "take this pill or do this cleanse and all will be well," is appealing. I'm not judging people for locking onto a trend that may help with some of these lifestyle factors. What surprises me, though, is the eagerness with which people adopt these practices without dedicating even 30 minutes to understanding the supporting evidence. Social media, like most of our problems, is likely largely to blame. In the era of :30 reels, it's difficult to have a nuanced discussion about anything, let alone a somewhat complex scientific discussion filled with nuance.

Anyways, I'm done babbling. That's what I'm here for, I guess!? So let's dive into it. Not headfirst though. These troughs aren't particularly deep!

When it comes to cold water immersion (CWI), there's a reasonable amount of intriguing research that provides insights into the effects of exposing our bodies to near-freezing temperatures for extended periods.

The Claims:

The most popular claims I've seen on the internet related to the benefits of CWI include the following:

• Boosts brain health

• Increases metabolism

• Reduces inflammation

• Aids in recovery

I'm sure there are many more, but these are the most popular that I've seen, and that's really all I have time to investigate. :-)

Is CWI Good For Our Brains?

Anecdotally, I've been using, let's call it, cold exposure lite, for years. Whenever I'm in a funk or a bad mood, I take a shower as cold as possible, focusing on deep, steady breathing to combat the instinct for rapid, shallow breaths. Within seconds I feel my mood change significantly for the better. I was never really sure how it was doing this. I remember reading a Tony Robbins (I went through a phase) years ago where he said, "If you want to change your psychology, change your physiology." Meaning, if you want to change your mood, put your physical body through some challenges. Fast forward 10 years, and we now have a full-blown social media trend on our hands!

New studies on CWI are popping up left and right these days. Among them, I enjoyed reading a study published in Biology in 2023. This study found that participants felt more active, alert, attentive, proud, and inspired and less distressed and nervous after a cold-water bath. The changes in positive emotions were associated with the coupling between brain areas involved in attention control, emotion, and self-regulation, suggesting that short-term whole-body CWI may have integrative effects on brain functioning, contributing to the reported improvement in mood.

Does CWI Increase Metabolism?

The short answer is yes, it does. The longer, more disappointing answer is that CWI increases metabolism for about 5-10 minutes, and 10 is being generous. I think this claim stems from a scientific principle known as thermogenesis. In the simplest terms possible, thermogenesis is the process by which the body produces heat. If you've ever experienced an extremely high fever before, you can appreciate how sensitive our bodies are to temperature. Mild hypothermia starts at around 95º F, and heat exhaustion can occur just above 100º F. About 5 years ago, I had a fever of 104º and was experiencing full-blown hallucinations. It was awful. Anyways, you probably get the point. Core temperature regulation is CRITICAL to our survival. So when we expose ourselves to external temperatures that are above or below about 98º F, there are physiological processes that occur to ensure our survival. If we are in a 200º sauna, one of the first things our bodies will do to cool us down is sweat. When exposed to cold, the body activates thermogenic processes to maintain core temperature. Two key mechanisms are involved:

Shivering Thermogenesis: Cold exposure triggers shivering, which are involuntary muscle contractions generating heat. As muscles contract, they burn glucose and fatty acids, increasing the metabolic rate to produce heat and maintain body temperature.

Non-shivering Thermogenesis: This occurs mainly in brown adipose tissue (BAT), which is specialized for heat production. BAT contains a unique protein called uncoupling protein-1 (UCP1) that allows the mitochondria in these cells to produce heat instead of ATP (energy) when burning fats and sugars.

Both mechanisms elevate the body's metabolic rate to counteract the cold, ensuring the core temperature remains stable.

Cool, right? I agree. The only problem is that, on average, you're only going to burn an extra 60-250 calories PER HOUR. The number varies so much because it's based on factors like your basal metabolic rate, which varies widely among individuals. So your 3:00 dip into the cold tank is burning a whopping 1-40 calories.

So if you're taking part in CWI for the sake of burning extra calories, you aren't wrong. But on the other hand, you could net the same caloric burn by eating one less peanut or walking 5 extra steps per day. The choice is yours.

Does CWI Help Lower Inflammation/Recovery/Reduce Pain?

When you sprain your ankle, you put ice on it, right? It lowers inflammation and increases the rate of recovery, or so we've been told. Over the last decade or so, this claim has been challenged by some very intelligent, well-known medical minds. Their main point is pretty straightforward. Cold exposure tends to slow things down, including blood flow, lymphatic fluid, and other cellular processes that are pivotal for recovery. Based on the studies that I could find, the results were quite varied. One study published in the Journal of Physiology in 2017 found that CWI was no more effective than active recovery (i.e., walking) in minimizing inflammatory and stress responses in muscle after resistance exercise. Another study published in Nature in 2018 found that repeated bouts of CWI did not alter systemic inflammation or muscle function recovery. On the other hand, you can find studies like this meta-analysis published in Frontiers In Physiology in 2018 that suggests that CWI could be effective in reducing some inflammatory markers, contributing to muscle soreness and fatigue reduction. At the end of the day, the disappointing answer to whether or not CWI lowers inflammation and aids in recovery is, we just don't know. It's possible. Based on what I've read, my inclination is that, like the metabolism-boosting effects, the degree to which CWI moves the needle in recovery in any real way is extremely minimal. I'll be happy to be wrong when presented with new evidence!

I believe there is a benefit to CWI that is very difficult to study and something I have rarely heard discussed. As a society, very little is required of us that is physically difficult. We don't need to stalk our prey and drag dinner back miles at a time. We don't have to go tend to the field to get our potatoes. I personally don't even do my own grocery shopping and I have 3 robot maids vacuuming and scrubbing my floors everyday. My point is, we don't experience many physically difficult things. And I'm not complaining. I hate grocery shopping, let alone working in a field all day. I believe an unintended byproduct of this ease of life is that when it comes time to do something that is difficult, we are more conditioned than ever to avoid it. The really unfortunate part about that is all the things that, as a society, we desperately need to improve (obesity, heart disease, diabetes, etc.) require us to do difficult things we probably don't want to do. Sitting on our asses, watching Netflix, and eating Five Guys is very appealing. But that doesn't undo the colossal health crisis we are living through at the moment. In fact, it makes it worse. We need to get better at sacrificing present comfort for long-term reward. This is where a very overlooked benefit of CWI lies. If you can regularly will yourself to get into a freezing cold tub of water and sit and breathe for minutes at a time, you are getting better at doing something that you really don't want to do. You are getting better at tolerating discomfort. I don't think that has ever been quite as valuable as it is today.

Until next time,

Jake Louro

Louro Training