«If we always choose comfort, we will never learn the deep capabilities of our mind and body.»- Wim Hof

Hot water is a recent invention. Unless they lived near some ancient hot springs, the first humans bathed naturally. These same humans conquered much of the planet at the end of the last ice age. Our genes were forged in adversity, and they deteriorate with excess comfort.

In today’s article you will understand the benefits of reconnect with the cold and how to make it your friend.

Hotter houses, fatter bodies

The explanation official One of the obesity epidemic is that we eat more and move less. To a large extent it is true, but there are many other aspects.

Defending ourselves from the elements always involved a great energy expenditure, until the arrival of a modern invention: central heating. Its use has brought many benefits, of course, but it has alienated us from an old friend: cold.

The interior temperature of our houses has risen several degrees in a few decades (detail), narrowing our thermal comfort zone and stunting our ability to cope with the natural environment.

Average house temperatures have risen, and the thermal range to which we are frequently exposed has narrowed

The thermal monotony it makes us spend less calories, for example, and many studies conclude that this comfort is an additional cause of the obesity epidemic (study, review, review, review, review, review).

As this review describes, we live in a ‘obesogenic thermal environment », and our health will benefit from lowering our body temperature from time to time. Let’s review some of the benefits of cold.

Metabolic benefits

To begin with, the cold raises the adiponectin, a protein released by adipocytes that stimulates fat burning (study, study). Low levels of this protein are associated with insulin resistance and obesity (study, review, review). Its increase is associated with greater longevity (review, study).

Exposure to cold significantly raises metabolism (study, study), facilitating fat burning (study, study).

Part of the increase in energy expenditure comes from brown adipose tissue or brown fat (detail). Unlike our hated white fat, brown fat is rich in mitochondria, and its specialty is convert calories into heat (detail, study).

In comfortable modern society, this fabric almost always remains inactive, since to awaken its potential we must give it a reason. And the main reason is the cold.

The lower the temperature, the greater the activation of brown fat. Source: https://www.nejm.org/doi/full/10.1056/NEJMoa0810780

At birth we cannot shiver, so babies have a lot of brown fat for protection. We lose some of this fat as we grow up, but if we never expose ourselves to the cold, the loss will be much greater, increasing the risk of obesity (detail).

In this study, important differences were observed in the amounts of brown adipose tissue in adults. When exposed for two hours to a cool but tolerable temperature, 19ºC, those with the most brown fat burned 250 additional calories during this period.

Brown fat is concentrated in the neck and clavicular area. Those who have more burn more calories when exposed to the cold. Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3726164/

Note: Although cold is the most direct way to activate brown fat, exercise seems to also have a slight effect (review, study).

In addition to raising metabolism, exposure to cold improves insulin sensitivity (study).

Evidently the cold will never compensate for a bad diet or a sedentary life, but it is an additional factor that will help us (study, study, review).

We actually see a inverse relationship between activation of brown fat and increase in white fat (study), but the direction of the relationship is not clear. Does white fat accumulate by not activating brown fat or is brown fat destroyed by gaining weight? Both may be true, but be that as it may, activating your brown fat will help you.

The more white fat, the less brown fat. Source: https://www.nejm.org/doi/full/10.1056/NEJMoa0808718#t=article

Improves mood

Exposure to cold raises levels of norepinephrine, dopamine, and beta-endorphins, improving the wakefulness and attention. This makes cold showers an effective treatment for symptoms of depression (study, study, study, study).

Like heat, cold releases heat shock proteins. One of the most studied is RBM3, which in animals has a neuroprotective role (study, study, study, study). It is not clear if the effect is so direct in humans, but it is an intervention used in the case of brain trauma (detail, detail).

In animals, a higher expression of these proteins lengthens life (study, study), and we have a lot of observational evidence in humans in the case of saunas (detail).

Reduces inflammation

Low-grade systemic inflammation contributes to almost all modern chronic diseases, and its reduction is associated with increased longevity (detail, detail).

Specific exposure to cold helps reduce this inflammation (study, study, study, study).

In fact, part of the improvements in depression may also come from less brain swelling (detail, detail).

Regulates the immune system

Our immune system also seems to benefit from the cold challenge:

  • Three fresh water dives a week, for 6 weeks (one hour at 14ºC) increased the number of cells of the immune system (study), as did exposure to environmental cold: 4-5ºC for 1-2 hours (study, study).
  • People who swim frequently in cold water have more white blood cells and monocytes (study).
  • Thirty days finishing the shower with cold water reduces absences from work (study).

Strategies to take advantage of the cold

Don’t go uncovered in winter, but do not protect yourself excessively. Wait maybe a little longer before putting your jacket on when it starts to cool. At home, try to pass at least a couple of hours at a temperature below 19ºC. It is tolerable for most but it is already an interesting stimulus (study).

Do not be constantly cold, but do not overprotect yourself

The main message is that we do not seek chronic exposure to cold, but specific stimuli. That is why I am a supporter of the cold shower, being a punctual stimulus easy to regulate.

You can start by finishing your normal shower with 30 seconds of warm water. Over time you lengthen the duration and lower the temperature. A reasonable thing would be to finish with two minutes of cold water, or showering directly with “cold” water during the summer.

And of course, nothing beats bathing in nature. Whenever you have the opportunity to get into a frozen lake, take advantage of it.

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After 6 hours of walking on an empty stomach, swim in the lake (cold 😋). This is #saludsalvaje 😂

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Immersion in water at 14ºC already produces a pronounced hormonal response (study), and most studies use temperatures between 5 and 15ºC.

As always, progress gradually. Start with uncomfortable but tolerable temperatures for 30-60 seconds. If you start to shiver, get out, your body has already received the necessary stimulus.

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Me trying to convince myself that the water is not so cold 😁 #hormesis # cold #wimhof

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Finally, the cryotherapy, which exposes you to temperatures below -100ºC, but colder is not necessarily better. Adjusting for time, plain water seems more effective than sophisticated cryotherapy (study, study).

Cryotherapy is not necessarily better than plain water

When? O Cold and Training

The cold activates us, making a cold shower a great way to start the day. More cold water and less caffeine?

The only time where I would apply caution would be around strength training, since cold is a double edged sword.

Exercise raises inflammation and oxidative stress (study, study). This short but steep lift is not only not bad, it is necessary. It is precisely one of the signals that trigger muscle adaptations.

But as we saw, cold reduces inflammation and raises the body’s antioxidant capacity (study, study). Generally speaking this is good, but not necessarily after training (or an injury).

In this study for example, subjects who soaked in cold water after training (10 minutes at 10ºC), they gained less muscle mass than the others. Other studies confirm this less adaptation (study, study, study).

Those who immersed themselves in cold water after training (CWI – Cold Water Immersion) gained less muscle mass. Source: https://physoc.onlinelibrary.wiley.com/doi/epdf/10.1113/JP270570

But on the other hand, cold can facilitate short-term recovery (review, study, study, study, study), being interesting for example during a competition that requires facing different events in a short time (study). In this case fast recovery is more important to us than subsequent adaptations.

The impact is also likely to depend on the type of physical activity. For example, exposure to cold activates AMPK and could enhance mitochondrial biogenesis (study, study), more relevant in endurance sports. And at least two studies in cyclists show performance improvements with exposure to cold (study, study).

Note: I personally finish the shower with cold water even after strength training, as it represents a far less stimulus than soaking in ice water for ten minutes, which is what they do in the studios.

Note 2: If you live in Burgos or Teruel, the cold shower concept takes on a special dimension in winter (detail). Adjust the temperature to your geography.

The psychological benefit

As we saw, getting out of our thermal comfort zone frequently benefits the body, but also the mind.

Inside you there is a constant fight between your rider and your elephant (detail). The rider is rational and thinks in the long term. The elephant is emotional and moves more for pleasure and comfort. The rider wants to do the right thing, the elephant the easy thing.

Every time you force yourself to do something you don’t feel like doing, your rider gets stronger. Every time you allow yourself to be overcome by comfort, your elephant win.

The time to turn the shower faucet is a good reflection of this fight: the rider knows that you will benefit from the sacrifice, but the elephant is frightened by the cold. Your response at that moment is more important than you think. Exercising discipline in the small decisions of each day will impact all aspects of your life.

As Viktor Frank said, «Between the stimulus and the response there is a space. In this space is our power to choose our response. Our answer is our growth and our freedom ». Every now and then choose the cold.

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The Stoics understood the concept of Hormesis. Exposing ourselves to small stressors (intense and brief) strengthens us. Voluntary discomfort prepares us for the arrival of forced discomfort. Or as they say: “the more you sweat in training, the less you’ll bleed in battle.” #hormesis

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