Studying the Wim Hof Method

As promised in my introductory post, I will start sharing the data I’ve collected from my experience with the Wim Hof Method (WHM).  It’s been a latent fascination for years, but only now have I had the time and focus to develop a proper obsession around it.  I’ve spent that last week doing a couple hours of “meditation” per day, and a few more hours hacking USB sensors and scripts to try to get a glimpse of what’s going on in the body.

If you haven’t watched the VICE documentary on Wim Hof’s website, I recommend you do before you continue.  Even if you have no interest in ever trying WHM, it’s really interesting to see what’s possible with your mind, and especially the fact that Wim Hof has been able to teach others to do it.   This includes not just withstanding extreme cold temperatures, but improving athletic performance, and direct control/boosting of your immune system (check out the endotoxemia experiment).  I hope to be one of those that learns it.

Back in 2012, before Wim was as widely known as he is now, my wife and I went to a seminar he put on in California.  We paid about $400 each for a 3-day seminar where he taught his breathing technique to about 12 people, and then had us do all kinds of exercises and cold exposure challenges.   This turned out to be a lot of fun, but we didn’t feel like we got a lot out of it besides learning the breathing technique and setting a baseline for evaluating future improvement.  For instance, I learned that my baseline was I can hold my breath for 24 seconds of extreme pain submerged in ice water!

So I recently bought his 10-week WHM-video course for $199, and decided to cram as much as I can while I still have time off before my next job starts.   Amazingly, I’ve already seen benefits in one week!  On day one, I had to take a 30-second ice cold shower after “pre-heating” in a warm shower.  I struggled for 20 seconds to get my gasping reflex under control and barely made it to the end, in pain the whole time.  A week later, I took a 60 second ice cold shower before and after the warm shower, experienced no gasping at all for the whole 2 minutes, and actually felt … dare I say, “good?”.   And more importantly (and usefully), it seems my hands are no longer cold all the time in the winter.  I believe the training has led to blood vessels in my hand staying open instead of closing when my I start to feel cold.   I wish I’d done this years ago!

Better, I’ve been able to demonstrate most of the progress through various measurements.   I used the “TEMPer1” USB thermometer, which I bought about 10 years ago for something completely unrelated.  Not only did I still have it, I was also able to find some simple python scripts to talk to it in Linux.


TEMPer1 USB Thermometer

After checking that it measures ice water and boiling water accurately, I trusted it would be satisfactory for my purposes.  You’ll see in one of my charts that its resolution is not great (0.9 deg F), but enough to capture the relevant trends.

But first…

The Breathing

Everything in the Wim Hof Method comes down to the breathing.  In a nutshell, the technique requires you to breathe rapidly and deeply for 30-40 breaths, or until your fingers start tingling.  It resembles hyperventilation, but is deeper and slower.  In fact, it is very much like the breathing you do when you exercise hard and feel “out of breath.” What makes it different than exercising is that you are accelerating oxygen absorption without an immediate need for it.

However, the “meditation” really starts once you hit a particular O2/CO2 ratio in the blood to become light-headed and tingly.  It’s at this point that you exhale completely and stop breathing.  You are “holding your breath” but without a breath in your lungs.  Wim Hof refers to it as “exhale retention.”  Most hobbyist breath-holders tend to practice “inhale retention” to get the longest continuous time possible without breathing (usually following hyperventilation).  The key difference with this method is:

  • It’s not a competition to retain for the longest amount of time
  • Your goal is to fully relax and listen to your body (easiest without the pressure of full lungs)

In everything Wim Hof does, it’s always “listen to your body.”  If you need to breathe, breathe.  If it’s uncomfortable, stop.  Don’t push yourself.  Besides the cold exposure–which gets easier over time–it makes the entire program a very pleasant experience.

Once you get the distinct feeling that you need to breathe, you inhale once, and hold it for 15-45 seconds.  Then release it and start the cycle again.  If this was a python script, it would look something like the following:

while isMeditating:
    while not isTingly:
    while isComfortable:
        time.sleep(1)  # with practice, will be 2+ minutes!

    time.sleep(30)  # 15 to 45 seconds

In his 10-week course, Wim encourages 3-4 times per session, for about 20 minutes.  However, he is eager to emphasize that you can (and he does) do this for much longer, up to many hours.  The longer you do it, the deeper you go, and the more enjoyable it is.

What is the point of this breathing?  Honestly, the direct link between the breathing/meditation and the target super powers is not immediately clear.  He claims that you get better control of your immune system and nervous system during the meditation.  All of the stress-inducing activities he does always comes after the meditation (but not during).  It’s part of my goal to color in the gaps in this understanding.

Some Data

With this backdrop in place, I wanted to share some of the first two measurements I took while doing this meditation.  As I’ll explain in the next post, I follow up the WHM breathing with a variant of Wim Hof’s exercises, which is essentially a meditative state focused on generating adrenaline.  My hypothesis is that my “adrenaline focus” sessions are successful due to the prior WHM breathing.

Test #1 – Day 3 of Workshop

I hooked up the USB thermometer with a simple script to sample the temperature once every 10 seconds.  I then taped the temperature probe to the back of my middle finger.  Once the temperature stabilized, I did 40 min of WHM breathing followed by 40 min of adrenaline focus.  Here’s the result:


Unfortunately, I didn’t add a mechanism for correlating WHM cycle time with measurement time, so the scale offset and the markers are approximated.  What you see here is:

  1. Start of WHM breathing.  Temperature rises briefly, then drops steadily over the course of the 40 minutes.
  2. End WHM breathing, and start adrenaline focus.  Temperature of the back of my middle finger rises 6-7 degress Fahrenheit!
  3. End of experiment, remove temperature probe from finger.  Probe returns to room temperature of ~64 deg F

This was extremely encouraging.  It shows that the WHM breathing reduces finger temperature, which Wim himself expresses: “exhale retention is not good for cold exposure”.  It also demonstrates that I was capable of raising my temperature back up with my mind.  It took about 20 minutes to get to full temperature.

Test #2 – Day 5 of Workshop

I’ll start with the data this time:


In this test:

  1. My fingertip temperature started high.  This was apparent over the course of the day, that despite being in cold rooms my hands were warm!  So I had to start the test with high finger temp.
  2. At this point I continued WHM breathing but switched from laying on my stomach to laying on my back.  When on my stomach, the other side of the probe is only an inch or two from the bed.  On my back the other side is exposed to the 64 deg room, so it makes sense that the temperature would drop.
  3. Stopped WHM breathing and switched to adrenaline visualization.  Finger temperature stayed constant for a couple minutes, then rose 6-7 deg F within five minutes!

One other observation here is the spikes in temperature as it was dropping during WHM breathing.  I believe this had to do with the 30-45 seconds of inhale retention I do at the end of each cycle.  I had already started associating deep inhales in with heat generation, and I think my body was starting to restore heat between cycles.  Unfortunately, the resolution of the temperatures sensor isn’t good enough to capture it fully.

Nonetheless, the absolute speed with which I restored fingertip temperature was amazing. It is not represented in the data, but I did confirm at the time that the room temperature was 64 deg Fahrenheit.  And it still only took only 5-10 minutes to get back to 88 deg F.

Up Next…

Since this last test, I have acquired a pulse oximter so I can add heart rate and blood-oxygen saturation to the charts.  I plan to collect some more data and explain more about the effect this had on the cold exposure challenges.

One thought on “Studying the Wim Hof Method

  1. I had surgery 3 weeks ago. I didnt do any breath-work but had a cold shower a few hours before and my blood saturation according to the doctor was 100% no biggy since normal is 95-99%. I did a sleep apnea thing in recovery and hit 72% saturation…just cause for a shot of something..but they are too cautious..all \i needed to do was breathe. The temperature stuff is interesting.


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