Cold Showers – Cold Thermogenesis

Benefits, how it works & how to get started.

Have you ever felt like you needed an iv-drip of coffee just to get going?

Ever had days where the brain fog feels like a quagmire of confusion?

Can’t face going out because you don’t want to feel cold?

Struggled to kick the flu every year?

Wondered how you could drop those last few sections of belly fat?

These questions are rhetorical! Of course, you have 🙂

Fear not though, for I present the solution to all your problems: Cold Showers!

That’s right a cold shower or cold thermogenesis for you technical lot. The very thought of it may send shudders down your spine and make your hair stand on end. But before you brush this off as unnecessary suffering, let me list a few benefits and give you my own personal experience of cold showers. At the end, I will also offer some different methods and a few pro tips 🙂

There are a host of benefits that come from frequent cold exposure done the right way.

To list a few:

  • Lowers body fat
  • Increases hormone levels
  • Improving sexual performance and fertility
  • Lowering blood sugar
  • Cutting food cravings
  • Improving adrenal function
  • Fixing thyroid issues
  • Enhancing immune function
  • Improving deep sleep quality
  • Increasing pain tolerance
  • Reducing inflammation
  • Improve emotional resilience
  • Reduce stress
  • Increase alertness
  • Improve your skin & hair
  • Improve circulation
  • Drain your lymphatic system
  • Relieve depression
  • Increases endorphins
  • Enhance muscle recovery
  • Vagus nerve stimulation

As you can see this is a pretty profound list of benefits, but why does switching the tap from comfort to pain offer such a myriad of goodness?

So how does it work?

Firstly we need to talk about an ancient pathway in the brain, called the mammalian dive reflex. The mammalian diving reflex optimizes mammals’ respiration to stay underwater for a long time. Every animal’s diving reflex is triggered specifically by cold water contacting the face, water that is warmer than 21 C (70 F) won’t cause the reflex, and neither will submersion of body parts other than the face. The diving reflex is a clever physiological mechanism enabling the body to manage and tolerate a lower level of oxygen. Three main changes occur in the body:

  1. Bradycardia, a slowing of the heart rate. The human heart rate slows down 10 – 30% and up to 50% or more in trained individuals.
  2. Peripheral vasoconstriction (a narrowing of blood vessels to reduce blood flow by muscle contraction in the blood vessel’s wall), causes reduced blood flow to the limbs ensuring that oxygen-sensitive organs like the brain and heart receive oxygen.
  3. During deep dives, a blood shift occurs allowing blood plasma and water to pass through organs and circulatory walls to the chest cavity to protect the organs from the increase in pressure.  The lungs gradually fill up with blood plasma, which is reabsorbed when the pressure drops.

This has a plethora of effects on the body but we are going to focus on nerve stimulation. When you activate your mammalian dive reflex it stimulates your trigeminal nerve.

This nerve is responsible for sensations in the face and motor control. The trigeminal facial nerves (5th cranial nerve) transmit the information to the brain which innervates the vagus nerve (10th cranial nerve) causing bradycardia and peripheral vasoconstriction. What you are doing is training your trigeminal nerve in your brain that there’s been an epigenetic change in your environment and it needs to start to pay attention to this. This forced adaptation is the catalyst for all the positive changes in the body.

You see we have become very comfortable as a species. We live in heated homes, have warm clothing, we can adjust temperatures at our leisure. While this is in itself an amazing advancement, is has come with a cost. We no longer rely on our bodies’ own innate ability to regulate temperature. We have survived for millions of years, in all the harshest of environments, all thanks to our incredible human technology that is our brain and body. Not experiencing this vital function on a regular basis has left us weak and sickness prone.

It’s all about stress. We need stress, stress makes us grow, stress makes us adapt, and stress makes us strong. Too much stress is not a good thing. But regular controlled stress is the ultimate catalyst for growth. When we train our muscles at the gym we cause stress which in turn forces them to grow stronger. It is the same for our bodies’ temperature regulators. As Wim Hof, the Iceman would say, “If you don’t want to get the cold, you have to get cold!”

We have special ‘shock proteins’ in our bodies’ that help us adjust to external temperatures. Heat shock and cold shock proteins. Whenever we experience a high shift in temperature the shock proteins kick in and start to aid the body in handling the situation. When you exercise you raise your body temperature thus activating your heat shock proteins. These proteins deliver the appropriate amino acids and other vital nutrients to the muscles. They also aid in recovery as well as a myriad of other benefits. This is one of the reasons saunas are so good for us. Similarly, cold shock proteins kick in when we experience cold temperatures. It’s in the continued and increased activation of these proteins that the beneficial magic lies.

But what about weight loss?

Let’s talk about warm-adapted biochemistry. You know that when there are three ways that our body stores energy. The first one is the very quick-acting creatine phosphate; the second one is glycogen in the liver and the muscles, which are the ones that most people talk about and that’s the one most warm-adapted exercise physiologists talk about. That fuels the replenishment of your ATP (adenosine triphosphate). When your glycogen depletes, the signal to your body is then to start to raise IGF1, which is growth hormone and testosterone. The reason why exercise has always been shown to increase lean muscle mass and eventually performance is that you’re getting a hormetic effect from glycogen depletion.

We have two types of fat, white fat, and brown fat. The oversimplified version is, white fat is the visceral fat that (in excess) causes health risks and is hard to lose. White fat is not bad, it has its benefits, just too much of it can lead to health problems. Brown fat is easily burnt off and metabolically easier to manage. Fat people have lots of white fat, but the cold turns the white fat into brown fat. There’s a physiologic change that occurs utilizing norepinephrine and epinephrine (fight and flight hormones). That turns it into brown fat, then you take the fat that’s in that white fat and you burn it as free heat, but there is no ATP made. So, you’re emptying your fat cells at the same time the cold also gets rid of the fat cells so that you become insulin sensitive. People who are already-fit don’t have to go through that. They will not usually convert a lot of their white fat that’s left to brown fat until they get to about, 6-8% body fat, in men, and about 15% body fat in women.

What happens then, instead of you burning calories as free heat from burning fat, you begin to have muscle shivering and that is when this ancient pathway in the brain actually stimulates TRH (thyrotropin-releasing hormone). It actually goes right above the thyroid. How this works is you stimulate something called uncoupling proteins 1 and 3.  You burn your glycogen off from your muscles just by shivering and it’s metabolically way more efficient to burn calories this way than it is to exercise. You can actually eat pretty much whatever you want as long as you can tolerate the cold (hyperbolic statement).

Increased Willpower

The other aspect of cold showers is the mental willpower. Doing something you don’t want to do, something that is difficult, something that is a bit painful, especially first thing in the morning, has a profound effect on your mental resilience. In the age of distraction having good self-discipline and mental willpower is not a luxury it is a must! Some days the thought of switching that tap from comfort to discomfort is difficult, but I have never done it and regretted it. In fact, that ability to do the difficult thing, to step into the cold, it carries through the rest of the day. All other difficult tasks transform into manageable, actionable options. In Wim Hof’s infamous words, “The cold is merciless but righteous!”

In my own experience, nothing tops a cold shower. Whether it is waking up, burning fat, feeling like a champ, or instilling self-discipline, cold showers are the way. Every morning and every evening I have a cold shower. I have been doing this for a few years and it’s the gift that keeps on giving. At the end of the day, you can read and watch everything you want about any topic, the best way to know it is to try it. Don’t take my word for it, go take the plunge!

How to have cold showers (not a redundant statement).

Depending on you and your body and your tolerance to the cold there are a few options to try:

Face Dunking – If you’re not used to the cold and find the cold extremely daunting then you will start to prepare yourself by running a basin of cold water and submerging your face in it. Once your face is submerged hold your breath for as long as you can, come out, catch your breathe and repeat. Do this a couple of times throughout the day for a week or so. This will be an introduction to the cold.

Straight Cold – Just step in and feel the cold glory. This is my personal preference 😉 

For beginners, I would recommend ending your shower with cold water. Start slow and build up, 10 seconds, 15 seconds, 20 seconds, etc.

Hot / Cold – Switching back and forth between hot and cold. 20 seconds cold, 10 seconds hot. This is also the best after exercise. Some people think a cold shower directly after exercise is not a good idea. Exercise causes inflammation and some inflammation is good, as it helps aid muscle recovery. There are benefits to both cold and hot showers after training. However, studies have shown that alternating between hot and cold after a training session allows for maximizing both benefits.

**Remember the body is dynamic, it is very advantageous to mix things up. Don’t be dogmatic in your approach to anything.

“The cold is merciless but righteous.” – Wim Hof (The Iceman)

Utilizing your breath is the most potent way to navigate difficult situations. Controlling your breathing will be a big component of this. The initial big breath is inevitable (as we mentioned earlier, it’s also good for you) but after that controlled breaths are advised. A good form of breathwork to master is the box breath.

Box Breath 

Breathe in for 4 seconds.

Hold for 4 seconds.

Exhale for 4 seconds.

Hold for 4 seconds.


Box Breathing Video:


I do not recommend prolonged cold exposure done over long periods of time.

(Anything 10 Minutes and over, done daily for extended periods)

There is research showing that a long time in the cold continuously can lead to weight gain. Which makes sense because your body is trying to survive. A 10-minute + cold exposure every now and then, great. Done every day for a long period of time, may lead to negative effects in the future.

Remember we all have different bodies and are in different places. Go at your own pace and pay careful attention to the changes in your body, mood, and mind.

Good luck 🥶