This post was going to be pretty long therefore I split it in two. The second part is here.
Man! Oh man!
My broscience detector has never been so much on the red side.
It's been around one year now that I kept hearing literally EVERYBODY talking about the benefits of cold showers. Any moments, I was expecting my grandma to mention them to me too. (well, it didn't happen)
Funny thing is that everybody is talking about them but nobody seems to actually know what they are talking about.
Check it yourself, google "cold showers" and check the first results. I was very much throwing things at my monitor.
Popular blog posts or magazines enumerating the marvelous effects of cold showers on your body that just penis enlargement was missing.
Few of them had links to scientific literature and apparently they thought "yeah, I'll just link this paper, you know. The title sounds good, nobody in my audience is going to read it anyway".
Guess what motherfucker? I read them and you are linking bullshit. Jesus if they got me pissed!
Therefore I decided, in this post, to put things in order and give a scientific validity for every claim made about the benefits of cold showers. It's worth noticing, though, that few studies have been performed so far on cold showers per se as most research is done on cold water immersion, therefore the results might be different.
Let's start off by debunking one of biggest myth about cold showers.
Cold Showers And Testosterone Myth
I bought into this cold shower frenzy initially for the speculated increase in testosterone levels that everyone was talking about. You know, I'm a guy, more testosterone sounds good to me. AM I RIGHT LADIES? *wink*
For the research I did for this post, I started looking for papers showing the evidence that cold showers or cold exposure would increase testosterone levels and you can't even imagine what I found out. What follows is how the cold showers testosterone myth was born.
Turns out that all those charlatans out there are citing this ethereal paper from the "Thrombosis Research Institute".
First of all, this paper is nowhere to be found and definitely NOT SUSPICIOUSLY AT ALL nobody that is citing it, does link to it.
Secondly, seems that this paper wasn't even published in a scientific journal but in a newspaper called The European. I can't confirm this but you can read my source here. Yes, you read correctly these useless pieces of shit are talking about science quoting a newspaper article.
Furthermore, these self-professed gurus of the Masculine™ are citing, as evidence that cold exposure boosts testosterone production, some papers in which it is shown that exposure of testicles to heat decreases sperms functionality.
WTF DUDE?!? That's not fucking evidence! If something is true, it doesn't mean that the opposite is true too. You can't infer this kind of things with such a freaking easiness.
It's like saying that since you die if you don't drink water, you are very healthy if you drink 20 liters of water per day. If you drink 20 liters of water per day you ARE GONNA FUCKING DIE. So, please, use your writing skills to comment cats' videos on YouTube and stop giving health advice because you "read somewhere on the internet one time".
Scientific Studies of Testosterone Levels in Relation to Cold
After some digging in Pubmed and Google Scholar I found several interesting papers in which testosterone levels are measured after cold exposure (some of them are done in humans, some in rats/mice).
- Physical exercise increases testosterone level in serum, but these tendencies were not found with cold water stimulation (10% decrease in testosterone upon cold water stimulation).
- Rats chronically exposed to cold-water immersion had decreased levels of testosterone (study, study).
- Rats exposed to cold-water immersion had lower ejaculation, lower testosterone, lower quality of spermatozoa (study, study, study).
- Runners and cyclists in a 160 km race across Alaska had higher cortisol and lower testosterone levels. It's noteworthy that this can just be caused from the great stress caused by the race and not by the cold.
- Meat-processing factory workers who spend around 3.5 hours per day in a cold room had lower testosterone levels. (Unfortunately the abstract is not available nor the full text for free)
All these papers say one thing: cold is bad for your balls and for your testosterone.
In some of these studies also cortisol levels were measured and guess what? They increased upon cold exposure. Now, if you don't know what cortisol is, this is a stress hormone. It's something you wanna keep low, especially for your gainz since it increases the breakdown of proteins therefore wasting muscle mass.
For the sake of scientific integrity I have to say that, from the studies cited, only the first one is performed on humans exposed to cold-water. In the other two studies on humans, they are exposed to cold-air and this might have a different effect than cold-water.
Most of the studies correlating testosterone and cold-water exposure are done in rats and this might not be translatable to humans.
Ah, some bros out there say that cold showers promote the secretion of growth hormone which helps making you big. No, this is another bullshit.
One thing is clear at the moment of this writing (November 2015).
There is no scientific evidence of a testosterone boosting effect caused by cold-water exposure.
Scientific data seem to report a lowering of testosterone levels upon cold-water exposure.
Cold Showers And Quality of Sleep
The other big one on the broscience front concerning cold showers is the fact that they make you sleep better. You'll easily see soon why this is nonsense.
If you have ever tried a cold shower you know how much you feel awake and alive after doing one. Personally, in those moments I curse every single ancient Celtic divinity and I make up new ones so that I can curse them too.
This is due to fact that cold water on your body causes the activation of the sympathetic system (study, review). Without going too much in details, I will tell you that this is a system in your body that causes the "fight-or-flight" response. This system is activated during stress, when we face a threat and we have to either fight it or run away from it.
During the activation of the sympathetic system, the chemical norepinephrine is released in your body and it serves the purpose to activate several systems. For instance:
- Your heart starts pumping blood faster so that your muscles will be ready to act faster
- Liver and pancreas start making more glucose so that you have energy to face the threat
- Blood vessels shrink (vasocostriction)
- Muscles increase their uptake of glucose (so that they have more energy)
- Brown fat tissue is activated (in the second part of this post I talk about this more in detail) so that more fat is burned and more heat is produced
So, tell me bro: do you want all of this shit before going to bed? Do you really wanna feel all pumped up like before doing an heavy squat set?
The sympathetic system promotes wakefulness and indeed during sleep it's when it has the lowest activity. How in fucking hell people suggest cold shower before sleep is a real big mystery to me.
I even found a post of Tim Ferriss suggesting this. First of all, let me tell you that I really like Tim Ferriss. I listen constantly his podcast and it gave me so many insights about a lot of different things and I'm very thankfully and I respect him. He's a smart dude with incredible curiosity and energy but I have to call him on this bullshit. Let's check what he writes in his post:
[...] Paradoxically, according to the Stanford professors who taught Bio 50, cold is actually a more effective signaller for sleep onset, but it could have no relation to melatonin production.
I decided to test the effect of combining 10-minute ice baths, timed with a countdown kitchen timer, one hour prior to bed (closer to bed and the adrenergic response of noradrenalin, etc. won’t allow you to sleep) with low-dose melatonin (1.5 – 3 mg) on regulating both sleep regularity and speed to sleep. [...] The result: it’s like getting hit with an elephant tranquilizer. Don’t expect it to be pleasant at first.
Author of The 4 Hour Body
(the emphasis in the quote are mine) I hope you lolled at this as much as I did. He proves that cold water immersion is good for sleeping while taking a medium-high dose of melatonin! You might as well have the Iron Maiden playing you the lullaby while taking that amount of melatonin and you'll prove that listening to heavy metal makes you fall asleep faster.
For my bros who don't know what melatonin here is a brief explanation.
It is also used as sleeping aid to help people with insomnia. The physiological dose is 0.3 mg while Tim Ferriss takes 5-10 times more of it and calls it a low-dose. He probably thinks he is a small elephant.
(Tim, if you are reading this, I'd love your opinion on it. I'd totally brodown with you bro)
One study also measured the levels of melatonin in subjects exposed to cold water after an intense session of training and didn't find any difference with a control which also indicates that cold water exposure doesn't help in sleeping better.
Why Warm Showers Are Actually Better For Your Sleep
This may sound new to you but what makes you doze off at night, is not only the melatonin that we talked about above. Also the temperature of your body plays an important role in making you fall asleep.
In a non-insomniac person, the core temperature (I swear to god scientists measure this by sticking a thermometer in the tested person's butt) reaches a maximum before you feel sleepy and then all of the sudden starts dropping and while it's dropping you feel more and more sleepy and eventually fall asleep.
(Image from this study)
Around 5-6 hours later, your core temperature will reach a minimum and you will wake up 1-3 hours after this, with your core temperature rising again.
One interesting thing to notice is that your body lowers the core temperature by transferring warm blood to vessels in the skin so that the heat can be transferred to the environment more rapidly. The vessels that do this best are the one in distal part of your body: feet, hands, lips, nose and ears.
And do you know how your body brings more blood there? It opens these vessels more so that more blood can flow there. That's why, if you have a warm bath, or just a warm bath for your feet (another study here) or even just put one of those ugly hot water bottles on your feet before going to sleep (although if you do this I'll never talk to you again), you will fall asleep faster.
So, if you take a cold shower before your sleep, you will activate the sympathetic system which causes these blood vessels to shrink and you'll get the total opposite effect!
Cold showers cannot make you fall asleep faster but they might promote wakefulness.
Warm showers are recommended to make you fall asleep faster.
Cold Showers And Depression
And here my friends, the exaltation of the broscience as fine art.
I seriously couldn't believe my eyes.
Almost every single website talking about how swag the cold showers are, talk about their mood improving effect, stating that they can be used to treat depression. And all of them cite the same paper from 2008: Adapted cold shower as a potential treatment for depression.
First of all, "potential" means that "it could happen" no "it is a fucking truth, trust me brah and shut up 'cause I have done experiments and shit".
Secondly, and here lies the genius my friend, the genius! The paper is published in a journal called "Medical Hypotheses". Godfuckingdamn HYPOTHESIS!!
It means that scientists write in this journal talking about ideas they have and how they could be proven and stuff.
IT'S JUST ABOUT FUCKING IDEAS!! They haven't done any experiment, they haven't put any thermometers in anyone ass.
Here's a quote from a very popular online magazine about this paper (they write that the paper is from 2007 but they link to the same paper I mentioned above):
A 2007 study published by a molecular biologist named Nikolai Shevchuk found evidence that cold showers can help treat depression symptoms, and, if used regularly, might even be more effective than prescription antidepressants.
I agree on the fact that after a cold shower you feel reinvigorated and ready to defend the Thermopylae but from this to say that you can cure depression which is a disease is a fucking huge leap.
Science hasn't yet (as of November 2015) proved that cold showers can cure depression. The paper cited by everyone talks about the possibility, not the actual fact. It might turn out to be true but at the moment, this hasn't been tested experimentally yet.
Would you please take 30 seconds of your time and answer below why do you take cold showers?
Listen to me bro, we are in the hands of broscientists all over the place. That's why I created this website and what I want you to learn. Don't trust what people write or say without checking their sources. Also me. Don't fucking trust me, click on the links I provide and read the scientific research by yourself. Start developing a critical attitude and you won't be a sheep following the pack but you'll be a leader.
We saw the downsides of cold-showers according to science and we debunked all the bullcrap on the internet that every one is talking about without having done their homework. Well, I've done them for you because I'm a bro but I also like the truth and facts.
In the next
If you don't wanna miss posts like this one, leave your email below!
Are you ready to take action and become superhuman?
P.S. If you want to be coached by me and you are badass, committed