Winter Swimming & Sauna: A Timeless Ritual Now Proven by Research

Cold plunging has deep roots in Nordic—and especially Finnish—culture. But one Scandinavian researcher, Susanna Søberg, has helped the world understand why this practice is so powerful.

A metabolic scientist with a PhD from the University of Copenhagen, Søberg has become one of the leading voices in cold-exposure research. Her book Winter Swimming explores both the culture and the science behind cold immersion and sauna, drawing heavily from Finnish winter swimmers and traditional heat-cold cycles.

What Søberg Discovered About Cold Exposure

1. The Søberg Principle

You don’t need extreme cold to see benefits.
Her work shows that 11 minutes of cold exposure per week, paired with about 57 minutes of heat, is enough to create meaningful physiological changes.

2. Cold Activates Brown Fat

Cold plunging wakes up the body’s “metabolic engine,” increasing brown-fat activity—supporting better energy use, heat generation, and blood-sugar regulation.

3. It Builds Stress Resilience

Brief cold exposure strengthens the nervous system, helping people stay calmer under stress and return to baseline more quickly.

4. Cold + Heat Is the Winning Combo

Her research confirms what Finns have practiced for generations:
sauna + cold plunge + rest is one of the most effective cycles for whole-body wellness.

You can learn more about her work here:
👉 Søberg Institute — https://soeberginstitute.com/
👉 Huberman Lab Interview — https://www.hubermanlab.com/episode/dr-susanna-soberg-how-to-use-cold-and-heat-exposure-to-improve-your-health
👉 Published scientific research (PubMed) — https://pubmed.ncbi.nlm.nih.gov/34755128/

Why It Matters Here in Michigan

Michigan’s sauna culture, especially in the Upper Peninsula, has been shaped by Finnish immigrants for over a century. Søberg’s research gives scientific backing to traditions Michiganders have practiced around lakes, snowbanks, hot tu and wood-fired saunas for generations.

At Purely Nomadic Sauna Co., we see this rhythm every week—families and friends stepping from heat into cold, laughing, breathing deeply, and discovering resilience together.

Science Meets Tradition

Søberg didn’t just validate cold plunging—she explained why it works.

A few minutes of cold, paired with restorative heat, can:

• boost mood

• improve sleep

• strengthen metabolism

• build confidence and resilience

All without needing extreme temperatures or long sessions.

Heat. Cold. Rest. Repeat.
A timeless tradition with modern science behind it.