It All Started With the Wim Hof Method

A few years ago I saw a YouTube video about Wim Hof. I don't remember the details anymore, but I still remember being impressed by his records and his seemingly superhuman abilities. The video suggested that anyone could learn this – with the Wim Hof Method.

It inspired me enough that I downloaded the app immediately.

A Record on the First Try

I jumped straight into the breathing technique and was astonished: starting at 45 seconds of breath-holding, I improved round by round until I broke four minutes in round ten. Breaking personal records on my very first training attempt – that was a massive dopamine hit.

Riding that feeling, I looked for the next exercise and found the Cold Shower Challenge: three difficulty levels (Beginner, Intermediate, Hoffer) that build up over four weeks. I had plenty of confidence in myself and started with a custom setup of three minutes. I followed the instructions in the video: breathe very calmly, relax, look for what's pleasant about the cold.

I built both into my daily morning routine – 30 breath cycles, five rounds.

The Questions Came After a Few Days

Not because I was skeptical it was doing anything. But because I wanted to know whether there were measurable numbers I could use to track progress.

Does this make me healthier? Does it improve my immune system? Does it reduce stress? Does it boost my performance? Is the instruction of 30 breaths equally sensible for athletes and non-athletes alike? The app allows 5 to 60 cycles – are more cycles better? Are more rounds better? At what point does an effect even kick in? At the end of each round you're supposed to hold with air in your lungs for 15 seconds – is 15 seconds the right number for everyone?

I bought a pulse oximeter, tested different variants, and logged my oxygen saturation. Pretty quickly it became clear: dead end. A number on my finger doesn't answer any of these questions.

Searching Made It Worse

So I searched YouTube for answers. I found nothing satisfying – quite the opposite. I ran into more breathing techniques like box breathing, and that brought even more questions with it.

I came away with exactly one insight: breathing can have a calming effect and lower your pulse, and it can have an activating effect and raise your pulse.

So, a Book

My curiosity was still strong, and I wanted to finally understand something as fundamental as breathing. So I looked for a book and settled on Patrick McKeown's The Oxygen Advantage – specifically, the German edition, Erfolgsfaktor Sauerstoff, which is what I had in hand.

There I learned the basics, and some of my questions were already answered in the first few chapters. I read that I could measure my performance capacity via the BOLT score or VO₂max. The exercises are built up step by step with clear instructions – I liked that. A chapter on mental aspects and flow states also caught my interest.

Reading it was tedious all the same. Chapters that could be said in two sentences are stretched across two pages and more. On top of that, countless success stories that all resemble each other and wear you down over time. The 384 pages could probably have fit into fewer than 100.

The 27 Pages I Never Checked

Speaking of pages: the sources span 27 pages.

That's one of the reasons I initially thought everything in the book rested on a cleanly researched foundation. I hadn't checked a single one of those sources. The sheer size of the bibliography was enough to earn my trust.

That has stuck with me to this day – and it's the reason this site exists.

What Turned Up When I Actually Checked

The deeper I dug, the more criticism I ran into. In a secondary source (Medical News Today), I read that parts of the medical field dismiss the Buteyko method as pseudoscience. That sounded alarming.

But when I checked the primary sources, I found neither extreme. Burgess et al. (2011) reviewed 41 studies across four different breathing methods; for Buteyko, six randomized controlled trials were available, consistently showing a reduced need for reliever medication in asthma. The authors themselves write, though, that there are too few well-designed studies for a definitive assessment. The Australian health authority arrived at the same conclusion from the other direction: possibly fewer bronchodilators, but no consistent effect on lung function, symptoms, or quality of life – and insufficient evidence for clinical use.

"Pseudoscience" doesn't capture it. Neither does "proven."

And the BOLT Score?

That left the metric the book told me to use for tracking progress. There is no independent, broadly accepted validation of the BOLT score as a measure of CO₂ tolerance or physical performance in the academic literature. Kowalski et al. tested it in 2024 on 49 speed skaters from the Polish national team against a Wingate test and cardiopulmonary exercise testing – no significant correlation with any of the performance parameters examined.

The number the book had offered me as a progress check wasn't one.

Why This Site Exists

Out of all this, a principle emerged: in the health space, there are two kinds of information – the kind that feels good, and the kind that can be backed up.

Wim Hof delivers the first. A record on the first try, a dopamine hit, a challenge with three difficulty levels. McKeown delivers some of the second, but dilutes it with so many success stories that the actual content gets buried.

I wanted a third way: evidence-based, compact, without dopamine tricks and without padded success stories. That's why I started FIT-or-FAT.com. Here I check sources, put effects into context, and only write what can be backed up – and I label how well it's backed up alongside it.

Because that's the actual lesson from this story: if you check sources, you rarely get a clean yes or no. Most of the time you get a maybe with conditions. That's less satisfying than a promise – but it's what's actually there.

How things went from there with breathing techniques is in the Breathwork Compendium – now in two volumes, free and without a paywall.

Sources

• Burgess, J., Ekanayake, B., Lowe, A., Dunt, D., Thien, F., & Dharmage, S. C. (2011). Systematic review of the effectiveness of breathing retraining in asthma management. Expert Review of Respiratory Medicine, 5(6), 789–807. DOI: 10.1586/ers.11.69
• Kowalski, T., Rebiś, K., Wilk, A., Klusiewicz, A., Wiecha, S., & Paleczny, B. (2024). Body Oxygen Level Test (BOLT) is not associated with exercise performance in highly-trained individuals. Frontiers in Physiology, 15, 1430837. DOI: 10.3389/fphys.2024.1430837
• Australian Government, Department of Health and Aged Care: Natural Therapies Review 2024 – Buteyko evidence evaluation. Cites the 2015 evidence assessment.
• Medical News Today: Buteyko breathing: Benefits, drawbacks, how to do it.
• McKeown, P. (2015). The Oxygen Advantage. William Morrow/Piatkus. German edition read: Erfolgsfaktor Sauerstoff, riva, 2018, 384 pages.