The human body is a MACHINE—an incredible, high-functioning, always-working engine with thousands of complex processes designed to help you thrive. But most of us? We’re running in energy-saving mode. We’re not tapping into half of what we’re capable of.
So, want to know one of the fastest ways to wake up that powerhouse system of yours for a boost in metabolic activity? Jump into cold water. Yep. You heard me. Take the plunge.
The Science Behind Why Cold Plunging Works
Let’s break it down. When you expose your body to cold, it’s not just about feeling tough. You’re triggering something called thermogenesis—the production of heat inside your body. Think of it like flipping the switch on your internal furnace.
And here's the fascinating part: There are two kinds of thermogenesis happening in your body when you brave the cold:
- Shivering thermogenesis — when your muscles do their little dance to warm you up (NIH)
- Non-shivering thermogenesis — the real superstar, driven by something called brown adipose tissue or BAT (PubMed)
When you plunge into cold water, your body instantly shifts into survival mode. Your muscles contract thousands of times per minute while you shiver—like a micro workout—and your metabolism goes through the roof. You’re burning calories just sitting there. In fact, according to a clinical trial in the European Journal of Applied Physiology, you can increase your own metabolic rate by up to 350%! How epic is that?
What is Brown Fat...
Now let’s talk about BAT. No, not the flying kind. Brown Adipose Tissue (BAT) is your body’s secret metabolic weapon.
When we’re infants, we have more BAT on our bodies—making up 2% to 5% of total body weight. BAT plays a crucial role in keeping us warm, as babies are more vulnerable to temperature changes. It's essential for newborns because they can't shiver like adults to generate heat, so BAT helps regulate their body temperature by burning fat to produce heat. This is especially important since infants have a larger surface area relative to their body mass, making them more prone to heat loss. (Cleveland Clinic)
During childhood and adolescence, the amount of brown fat reduces. As an adult, you have a small amount of brown fat. People who are lean, like athletes, tend to have more brown fat in their bodies than others. So what's the difference between BAT and white fat?
Brown Fat vs. White Fat
White fat, on the other hand, is more commonly found in the adult body and primarily serves as a storehouse for energy. It consists of large cells filled with fat droplets. While it can be used as an energy reserve when the body needs fuel, white fat isn't involved in heat generation.
In contrast, brown fat contains many more mitochondria than white fat cells, which makes it metabolically active. The high concentration of mitochondria gives brown fat its ability to burn calories. According to hhmi.org:
"Mitochondria harvest energy from sugar and fat, but when triggered by temperature, those in brown fat switch to heat generation. Making heat consumes energy, in the form of calories, that could otherwise be stored by its counterpart, white fat. According to conventional thought, this furnace-like function is responsible for brown fat’s substantial metabolic benefits: improving the body’s ability to manage sugar, fat, and cholesterol, and so reducing the likelihood of conditions such as type 2 diabetes and cardiovascular diseases."
This is why brown fat is often seen as a healthier type of fat—since it is actively working to burn energy, it can help with weight management and has been shown to play a role in improving overall metabolism.
Why Brown Fat Decreases with Age
As we age, we lose a significant portion of our brown fat. In infancy, we have more brown fat because it's crucial for maintaining body temperature and energy balance. However, as we grow older, the amount of brown fat in our bodies decreases, and much of it transforms into white fat.
Increasing BAT with Cold Plunging
Interestingly, it is possible to stimulate the production of brown fat—or activate existing brown fat—through regular exposure to cold temperatures. Cold plunging, or exposure to cold environments, triggers the body’s natural response to cold by activating brown fat to generate heat and help maintain body temperature. This process encourages the body to burn calories, which can help in weight management and improving metabolism (Plos.one).
As explained by research published in NIH, when you subject your body to cold, the shock activates the sympathetic nervous system, which can stimulate brown fat to work harder—potentially converting some white fat into a more metabolically active form of fat that behaves similarly to brown fat. This process, called browning of white fat, is one reason why cold exposure, such as cold showers or ice baths, is gaining popularity in wellness circles.
Consistent Cold Exposure = Lasting Change
Here’s what happens when you make cold plunging a habit:
- ✅ You boost your metabolism
- ✅ You train your body to burn more fat
- ✅ You build mental resilience
- ✅ You develop emotional regulation
- ✅ You feel calmer, clearer, and more capable
You become a more bada$$ version of yourself that achieves your health goals. Imagine your body literally burning fat while you breathe through the chill. That’s not hype. That’s biology!
Real Talk: You Were Built For This
Don't think cold plunging is right for you? Let me remind you of something: Your ancestors survived ice ages. They didn’t have heated seats, climate control, or electric blankets. They adapted. They got stronger. They evolved.
You’ve got that same power in you. So stop settling for feeling blah. Stop believing that low energy, weight gain, and brain fog are just part of life. They’re not. Your body is trying to wake you up—and the cold is your ultimate teacher.
💧 Join us in our 1,200-gallon group cold plunge.
It’s epic. It’s electric. And it’s waiting for YOU.
And if you’re new to cold plunging?
Don’t sweat it (literally — you’re going to freeze first 😉). We got you!
We’ve guided over 350,000 people through their first plunge. You are in GREAT hands.
Note: Always consult with a healthcare professional before beginning any new wellness practice, especially those involving extreme temperatures.
Shira Shane
Creative Director of Breathe Degrees, Director of Breathwork & Contrast Therapy Training
Breathe Degrees & XPT Certified Breath Coach
