Endurance Skating

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Cold Thermogenesis, Brown Fat, & The Cool Fat Burner Vest

That which doesn't kill you.. unfortunately this did kill him, so we'll never know.

Jack took his CT very seriously…

Cold Thermogenesis (CT) is the term being floated around by the coolest kidz for repeated frequent cold exposure, and is very much on the bleeding edge of our slowly expanding understanding of health and fitness. 3 years ago very few people were really talking about it, and 5 years ago you would have been hard-pressed to find anyone talking about it; however, now it seems that everyone from geeky biohacker to experimental sportsman is getting in on the CT act (Mo Farah has his own cryochamber)… and as I happen to tick both those boxes I obviously couldn’t wait to forego the creature comforts of modern life, strip myself naked in the middle of the December in a way that would make Bridget Jones blush and risk both hypothermia and arrest – all in the name of science, you understand.


It makes a lot of sense from an evolutionary perspective – humans evolved in what we would today consider harsh cold environments, and it is likely that we developed the ability to not only survive, but to thrive in such environments. Cold is just a specific form of physical stress, which leads to adaptations that advance the state of the organism.  Also, from my admittedly limited understanding of physical chemistry, cold is a superconductor, and since our bodies’ cells are governed by the laws of electromagnetism at the atomic level, it is not beyond crazy to suggest that many of our cellular level functions are likely to operate more efficiently in the cold. The creature comforts of modern life have turned most of civilisation into a race of pussies, but in the Himalayas there are still cultures such as the Tibetan Monks and the Sherpas who, thanks to their lack of modern central heating, live largely in perfect health, and are able to perform the impressive physical feats that they do.

The Crazy Luminaries Of CT

Wim Hof is perhaps the most famous practitioner of cold therapies to western audiences. The dude takes daily ice baths in freezing lakes and is a borderline crackpot, but there’s no denying that he’s a marvel of physical and mental toughness, holding over 20 world records for stuff like swimming the longest distance under a frozen lake, and running up Everest in nothing but a pair of pants. Scientists have shown that Hof has an ability to override his Autonomic Nervous System to do what he does, so maybe he is unique, but Hof himself says that there is no secret to his method, and that anybody can learn and benefit from the same practices.



Jack Kruse has written in great depth about the use CT in his blog-from-the-Twilight-zone, along with non-native EMF (basically get away from it), circadian rhythms (respect them), body-water chemistry (avoid fluoride), and pescatarian-based paleo protocol (eat shellfish and vegetables). CT1: Read more at the weird and wonderful world of Dr Jack Kruse.. 

Popular Health & Fitness gurus Ben Greenfield, Dave Asprey and the like are all-in on the CT bandwagon. Being cool is red hot right now.

Basic CT Protocol

The beauty and attractiveness of CT and its cast of colourful characters is that even if some of the theories behind it are a little head-spinning and require a small leap of faith, it’s as simple as pie to implement, and doesn’t have to cost you a penny.

 If you’re a total wuss, you can start out by dunking your face in some ice-water on a daily basis – as your nervous system is all connected, this helps condition the rest of your body.

From there, try changing up your daily shower routine with some alternating hot/cold blasts – try to get the water temperature down to around 10-12 degrees celsius on the cold blasts, and aim for a “10 second hot, 20 second cold” routine, repeated 5 or 6 times over (think of it as CT tabata).  The idea is that the hot/cold contrast will cause alternate vasorestriction and vasodilation of your arteries, veins, and capillaries, improving your cardiovascular and blood vessel function.  Once you can do this, you are well on your way to reaping the benefits of daily CT!

If you feel that you can easily handle a fully cold shower every morning or after every workout, it may be time to try the full ice bath – for example, after a particularly heavy training day, or a key workout session.  However, this is definitely not for the faint of heart.  I’ve only done this a couple of times myself, and I have to say that it’s probably not going to be a regular occurance for me. Note that you don’t need to go neck-deep, just enough ice-water to cover the legs and trunk is probably all you need. Even so, it hurts like a mothertrucker. If you can handle a 10 minute ice bath, you are a certified CT badass!

Cold air-to-skin exposure is of course encouraged, but if you are venturing outdoors, with fewer layers than most then firstly, don’t get caught for streaking, and secondly, you may want to still cover the extremities with gloves, hat & scarf, as that will blunt the feeling of the cold while not affecting the amount of CT exposure you are getting.

Lastly, you want to check the temperature of your bedroom and ensure that it is not too warm when you sleep – 18-19 degree celsius is optimal.


Cool Fat Burner

As part of my experiments with CT I bought the Cool Fat Burner (CFB) & the complementary Cool Gut Buster (CGB) vests.  Marketed as the “world first brown fat cooling vest” (more on brown fat later), the CFB project was brought to market via a crowdfunding project, and its creator – Eric G – is an interesting individual who totally espouses the N=1 mantra, using himself as a human guinea pig to demonstrate the benefits of CT and the CFB, all in the name of science (and profit).


coolfatburnerThe CFB is essentially a bib with pockets in which you place custom ice packs which cool you around the chest and back of the neck. The CGB works in much the same way, but straps around your waist in order to cool your torso and kidney-area of your mid-lower back. The CFB & CGB can be worn individually or both at the same time if you really want a deep hardcore CT session.  If you are just going to get one, I would recommend the CFB as that is the original vest that targets the “brown fat” area of the body.

coolfatburner2By wearing a combination of the CFB and/or CGB, you can induce various shiver states, which will boost your resting energy expenditure – anything from a mild shivering to a full-blown, goosebump forming, teeth-chattering amount of shivering.  At the higher level of induced shivering (or shiver-surfing.. see well cool innit), it is claimed that your base metabolism (calories expended) will increase by as much as TRIPLE, if you believe the N=1 lab test material – that’s as much as moderate exercise – hence it’s marketing as a “fat burner” device.  It’s the holy grail of biohack geeks allowing you to burn fat and get ripped while playing World of Warcraft!


However, the claims go beyond just being a fat-loss and body recomposition tool. The CFB vest also claims to:

  • Improves blood glucose control
  • Activate some important hormones, chiefly adiponectin and irisin, which are important in regulating sleep and tissue repair
  • Help to create and activate metabolically active brown adipose tissue (BAT)
  • Help control systemic inflammation
  • Improves recovery from exercise
  • Performs cellular apoptosis on white fat – ie, destroys white fat cells rather than just emptying them (which is the role of fat loss through diet), making it harder to regain the fat


..etc etc.. all of which means that by laying your hands on one of these babies you could be doing yourself a massive favour and ticking some important Primal Health checkboxes.

Brown Adipose Tissue

Brown Adipose Tissue (BAT) is very different to the standard white fat (WAT). BAT is formed and activated through mild cold exposure, and if you are lucky or healthy enough to have any BAT deposits – not everyone does – then it is the most metabolically active tissue if your body.  Unlike the far more ubiquitous subcutaneous and/or visceral types of white fat that can and does accumulate everywhere, BAT tends to accumulate around the neck and shoulders area, and is the one type of fat that you absolutely do want to have as much of as possible.

BAT in adults is a very recent discovery, only achieved with the introduction of Positron Emission Tomography technology – or PET scans – a few years ago.  Previously it was thought that BAT only existed in newborn babies (hence their ability to not die when left on Santa’s doorstep in just a diaper) and disappeared early on as the baby grew, but now it has been shown that adults can also possess high levels brown fat, and – furthermore – BAT deposits can be grown and created from white fat with moderate cold exposure.

Although you must always be careful of associational data, BAT level has closely shown to be highest in the leanest individuals, so raising your BAT levels is probably a good idea. It’s an exciting new discovery in the field of human biology, and fits into the thinking of those like me that the human body has mechanisms that will allow it to thrive under cold stress.


More on Brown Fat:


Dr Paul Lee

Cool Fat Burner

Does The CFB Work?

This is not a yes|no answer.  It definitely does something. If I put on the CFB & CGB and perform a deep CT session, I will typically notice that my heart rate will drop and that, more interestingly, my pulse will slow and my Heart Rate Variability (HRV) will increase, sometimes quite dramatically.  This definitely says that my body and my nervous system is responding in some positive way to the cold.


I don’t think I’ve noticed any difference in body composition, although I don’t have much weight to lose anyway. I suppose that if you were very clever it’s possible you could eat eat slightly more junky carbs and then use the CFB to shuttle the glucose into muscle storage rather than having it converted to triglycerides and stored in the liver. Ideally, you should use the CFB on days where real life interferes with ideals and you eat more junk than you planned in order to minimize the damage.


I think there is one thing the CFB (along with all the other CT tricks I do) really does help with (and I have read this from other reviewers too): SLEEP. I notice that on days where I have done all the CT tricks, I tend to sleep the best. Again, if you think about it hard, there are probably good reasons why this is the case – hormone balance, something shifting in the autonomic nervous system (hence my observation of a higher HRV), and change in external temperatures that reflect a normal circadian cycle all play a role in telling the body that it is time to sleep and regenerate.  I also suspect that better blood sugar levels control is also key to helping aid deep sleep.



Despite my full belief in Cold Thermogenesis therapies as a health and performance enhancer, at first I have to say that I was a little underwhelmed by the Cool Fat Burner.  It’s not particularly well manufactured, with the material seemingly quite cheap, and the design not that impressive (let’s say that Amani would be appalled), although the ice-packs are certainly an improvement on what you can buy from the high-street.  I do think that you can get a lot of the same effect if you stick a few cheap ice-packs underneath your skinsuit. However, after having used it for a couple of months, and experimented with the hardcore shiver sessions.. I think that it definitely allows you to take it up a notch further – but you need both the CFB AND the CGB on at the same time in order achieve the high-shiver state.

The CFB/CGB is also pretty versatile, and you can easily wear it around the house and outside – for example, I have had no issues sticking it on and walking to the shops still wearing it.

Overall, the way to use the CFB is not as a CT device in isolation, but as one of the tools in your whole CT toolbox. Whether or not it’s worth the money (I think I paid about £150 after conversion from the strong dollar and the excise duty) is up to you. As I said, you can get almost the same effect with if you get creative enough. So if you want to dabble in CT, I would say start off by taking cold showers, and then buy a few cheap ice packs, stick them down the back of your skinsuit, and see how you go with that arrangement for a couple of weeks. MTFU and do it!


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This entry was posted on March 25, 2015 by in Health, Science and tagged , , , , , , .

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