Fat LossFitness JourneysThe 4-Hour BodyWeight Loss

Use Thermodynamics to Lose Fat?

In his new book The 4-Hour Body: An Uncommon Guide to Rapid Fat-Loss, Incredible Sex, and Becoming Superhuman , author Tim Ferriss exposes a few simple ways that all of us can use temperature manipulation to supercharge our weight/fat loss. One of the ways Tim Ferris accomplishes this is by taking a 15 minute ice bath 3 times a week.

The idea is that your body naturally wants to maintain it’s homeostasis (internal stability) temperature of 98.6 F. By exposing your body to cold and decreasing it’s temperature, you’re spurring it to burn even more calories to create heat (heat = calories) as it tries to get back to homeostasis.

After being inspired by stories of swimmer Michael Phelps’ 12,000 calorie/day diet, Ray Cronise, a friend of Tim Ferriss and former NASA scientist, started including cold swims and shiver walks in his workout routine. The result? His weight loss TRIPLED as he went on to lose over 30 pounds in ONLY six weeks.

Living in a place like Minnesota, where the average Winter temperature is 6 degrees Fahrenheit, a shiver walk would be incredibly easy to incorporate into my fitness journey. For me it’s as Tim himself quotes in his book:

“This [approach] could be totally wrong, but it’s a hypothesis worth disproving.” -Dr. Noakes

BUT I’m curious what you think about adding an ice bath or shiver walk to your routine. Should we start our own shiver walk group? Are you likely to give it a whirl, OR do you think Tim is CrAzY or full of shit?

For more on the modern day Indiana Jones and superhuman that is Tim Ferriss, visit his official website at fourhourbody.com

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  1. What is the temp you need to lower to get a result? How long do you stay at the temp? If you lower your house temp, to what tmep and how long should you stay at this lowered temp?

  2. Hi Susan,

    Tim mentions several different methods in The 4-Hour Body for utilizing temperature manipulation to encourage rapid fat loss. In a study he references the participants used liquid-conditioned suits perfused with 60° F water for two hours. Tim also details his own experiments of taking 3 phase, 20 minute baths using two ten-pound bags if ice and his bath tub. However, his recommendations for introducing temperature manipulation into our own fitness routines are far less dramatic (and far less painful I imagine). For instance, he recommends taking 5 to 10 minute cold showers before breakfast and/or before bed (He includes tips to help make this as painless as possible).

    The main focus of temperature manipulation as I see it centers on inspiring a shivering response in your body, which I’m sure can vary greatly from person to person. For instance, being from Minnesota, I probably have a somewhat higher tolerance for cold than someone from say Jamaica. I plan on just starting with a 10 minute shiver walk and then adjusting as necessary from there. The high here today is 15° F, so I don’t suspect I’ll have much trouble getting myself to shiver. I’ll be posting results from my experiments with Tim’s techniques for those interested.

    For further details on temperature manipulation I recommend picking up a copy of The 4-Hour Body, and/or you can find more valuable information on the cold exposure experiments referenced at Ray’s site http://hypothermics.com.

    Thank you for the great questions and best of luck!

    -Lean Muscle Matt

  3. Thanks for the post Matt.

    As you have probably seen from my site, I did some of the extreme in the beginning, but have settled in on much more mild exposure. Having been to Minnesota and still not understanding the concept of ice fishing, I will say your adaptation is perfectly normal. In fact, you will find that you can tolerate much more cold environments, because of the habituation of exposure. As well, you will note that when your extremities are well insulated (noes, toes, fingers and ears) the core can take a LOT more exposure.

    Not unlike the coffee sitting in the cup holder, your body would cool rapidly if heat is not continually added. It is these little exposures all the time that have huge impacts. resisting the temptation to “cocoon” inside when the temperatures are not too far from what they might be on a good summer day is the key. Inside, dress in short sleeves and light clothing and outside, layer appropriately – beginning with the extremities – avoiding all but the slightest shiver. Bring layers with you and put them on – as needed.

    A lot of quality heat loss can happen in 80F water (24x more thermally conductive than air) and 50-60F air with minimal clothing. Your body will tell you when enough is enough and shivering uncontrollably will be your first clue.

    The KEY will be that these incredibly high caloric burn rates will induce hunger. Eat appropriately and you will lose weight. If you binge to compensate, then it all zeros out. Establish a good nutrition/exercise program and then add the additional thermal loads. You will notice the increase craving for food at first and that is your sign that your melting the fat away…


  4. Greetings Ray!

    I have to start out saying that I can’t help but feel a little starstruck that you’ve commented on my site. I’m extremely honored!

    My heartfelt thanks to you for clarifying your methods, especially the part about resisting the urge to compensate increased caloric burn rates with increased caloric consumption. I know that overeating can be a big problem for people who start working out with the intention of losing weight for that very reason.

    I’ll be posting a video in the near future of my first shiver walk, and I may do it on a lake by the ice-houses now that you mention it. :)I’m more of a spring/summer fisherman myself, so I can’t say that I completely understand what motivates my fellow Minnesotans to drag their little shacks all over the winter tundra. I’m pretty sure copious amounts of beer/alcohol has something to do with it.

    Your story is truly an inspiration for me, as I’m sure it is for everyone else who hears it. Thanks again for your invaluable contributions to this post.

    Best Regards,

    Lean Muscle Matt

  5. Very inspirational for sure. Since it’s 84° here in Southern California, walking outside in shorts will only make me look ‘normal’. I’m going to start with cold showers. Thanks!

    – BUM