Citation

Zwaag J, Naaktgeboren R, van Herwaarden AE, Pickkers P, Kox M. The Effects of Cold Exposure Training and a Breathing Exercise on the Inflammatory Response in Humans: A Pilot Study. Psychosom Med. 2022 May 1;84(4):457-467. doi: 10.1097/PSY.0000000000001065. Epub 2022 Feb 23. PMID: 35213875; PMCID: PMC9071023.

4 FUNDAMENTALS

1. Essential Background Material

In Part One of this study, we learned four critical pieces of information:

1. The anti-inflammatory effects of Wim Hof breathing can be achieved with or without breath holds.

2. They can be achieved using an independent instructor.

3. They can be achieved with only 2 hours of training.

4. They can only be achieved if practiced in the morning, not afternoon.

Those results are essential from practical and clinical perspectives. However, two critical questions remain.

First, will these results hold up when participants are injected with endotoxin? If so, this would be yet another monumental finding because it would mean people only need 2 hours of training from an independent instructor in one breathing method to reduce inflammation.

Second, cold therapy is a central component of Wim’s method, and it was used in the original PNAS endotoxin study. But, it’s unclear how much it contributed to the anti-inflammatory response. So, is cold therapy needed, or is breathing enough?

That’s what Part Two of this study aimed to find.

2. What Did this Research Do?

Forty-eight participants enrolled in the study. They were divided into four groups with 12 people each:

Cold Only: Intensive 4-day cold exposure training led by an independent trainer. No deliberate breath training.
Breathing Only: One 2-hour instruction of the WHM modified breathing technique. They were told not to practice this at home. They chose this one based on Part One, where both WHM breathing exercises produced similar initial spikes in adrenaline. The logic was that using the method without hypoxia would have broader applicability.
Cold + Breathing: Both above training programs: 4 days of cold training and one 2-hour breath training session.
Control: No training.

Endotoxin Administration Day

The Breathing Only and Cold + Breathing groups started the modified WHM breathing 30 minutes before injection. They continued it for 2.5 hours, for a total of 3 hours of hyperventilation. This is the same protocol used in the original PNAS study, except that only one breathing exercise is used here.

The Cold Only and Control groups did not perform any breathing exercises.

Like the original PNAS study, adrenaline, blood gases, inflammatory cytokines, and flu-like symptom scores were all recorded throughout the experiment.

3. What Were the Major Findings?

The table below summarizes the most important findings. The changes are comparisons with controls. So, if it says that inflammation improved, that means it improved compared to the control group.

Summary

* One inflammatory cytokine, MCP-1, was lower than the control group. This one was not measured in the original PNAS study.

4. Why Do These Results Matter?

These results are meaningful because they show that as little as 2 hours of Wim Hof breathing without breath holds can reduce acute inflammation due to endotoxin injection.

Moreover, they show that cold exposure alone does not reduce inflammation. However, the combination of cold and breathing has a synergistic effect, reducing inflammation more than breathing alone while also reducing flu-like symptoms.

We should note that the anti-inflammatory response was not as profound as in the original PNAS endotoxin experiment. There’s no way of knowing why. But, it could be that the WHM breathing with hypoxia, which has a more sustained release of adrenaline, works better when participants are exposed to endotoxin.

Lastly, note that this study did not measure baseline inflammation. So, cold therapy could potentially help there. These results just show that it didn’t have a significant effect when participants were exposed to intense short-term inflammation associated with the endotoxin.

1 BIG TAKEAWAY

Breathing is the primary pillar of Wim’s method that reduces acute inflammation during endotoxin exposure. However, cold training boosts these anti-inflammatory effects while also reducing flu-like symptoms.

1 PRACTICAL APPLICATION

NOTE: To use the method, it’s critical that you work with a certified Wim Hof instructor or obtain a physician’s approval to ensure you do not have any contraindications.

These results show that Wim Hof breathing by itself can reduce inflammation. So, if you’re completely against the cold, this suggests you can still use Wim’s breathing to get anti-inflammatory effects.

However, the results also show that using both cold and breathing has a synergistic effect of reducing inflammation more than breathing or cold alone.

What’s more, the results suggest that regular cold exposure may help with your ability to reduce flu-like symptoms if you become sick.

So overall, incorporating cold might be beneficial if you have an autoimmune disease or any condition that leads to chronic inflammation and increased susceptibility to illness. See the Book 411 on The Wim Hof Method for Wim’s basic cold exposure guidelines.