Cold Immersion for metabolic health: Unlock fat loss & activate your metabolism
Nutrition and exercise may steal the spotlight in weight loss, but cold-water therapy (CWT) is the ultimate supporting act. By activating brown fat – your body’s calorie-burning furnace – CWT boosts metabolism, improves insulin sensitivity, and helps you burn energy more efficiently.
Dr. Susanna Søberg, PhD, a leading researcher on deliberate cold exposure, has uncovered the profound effects of cold protocols on glucose metabolism, insulin sensitivity, and neurotransmitter release. Cold immersion triggers norepinephrine and dopamine, which not only enhance mood and focus but also kickstart your metabolism through a process called non-shivering thermogenesis. This protocol is designed to help you harness the fat-burning power of cold exposure and take your metabolic health to the next level.
Cold and fat: the science
Our bodies contain two types of fat:
- White fat (WAT): The stubborn kind that stores energy.
- Brown fat (BAT): A metabolically active tissue that burns calories to generate heat.
Without stating the obvious, your metabolism is how fast your body converts food into energy. Cold exposure activates brown fat, prompting it to burn calories from white fat and glucose to keep your body warm. In fact, one study found metabolism increased by 350% when participants were exposed to 14°C (57°F) water.
Higher levels of brown fat are linked to a faster metabolism. Cold exposure can push BAT deposits to increase calorie burning by 25-40% above basal metabolic rate, making it a powerful ally for weight loss and metabolic health.
A study on cold acclimation found a 43% increase in insulin sensitivity after just 10 days of exposure to 14-15°C water, demonstrating its potential for improving metabolic health over time.
For more on the science behind cold exposure and weight loss, check out this blog post.
The brown fat activation protocol
This protocol focuses on CWT to stimulate thermogenesis and unlock your body’s fat burning potential.
Step 1: Cold exposure for brown fat activation
- Temperature: The key is choosing a temperature that feels challenging but manageable. Beginners can start at 10-12°C (50-55°F) and gradually lower the temperature as they acclimatise. Our Acclimatisation Programme on our app will act as your cold water coach and guide you through this process.
- Duration: Stay in the water only until you begin shivering. This might be 30 seconds for some or a few minutes for others. Listen to your body.
- Tip: During your plunge, keep moving gently to break the thermal barrier that forms around you and maximise the perception of cold.
- Frequency: Aim for 2-4 sessions per week, depending on comfort and goals.
Shivering isn’t just a sign that you’re cold – it’s your body’s way of raising your metabolism. This activates brown fat stores, burning calories to generate heat. Over time, consistent cold exposure trains your metabolism to respond more efficiently.
Pro tip: There’s a difference between safe shivering and overdoing it. If you can consciously stop shivering with deep breaths and relaxation, you’re good. If not, it’s time to get out.
Why it works:
Cold exposure up-regulates norepinephrine, a signalling molecule that "switches on" BAT. This activation prompts brown fat to burn calories by metabolising white fat (WAT) and glucose for energy.
Step 2: "End With Cold" for maximum impact
- Avoid warming up immediately with a hot shower or sauna. Instead, allow your body to naturally reheat to prolong the calorie burn and activate brown fat further.
- Stand in cool air for 1-2 minutes post-immersion to encourage shivering for an additional metabolic boost.
Why end with cold?
“Ending with cold” extends the thermogenic effect of CWT and encourages a longer calorie burn post-session. Plus, it also builds mental resilience leaving you feeling more alert and in control after each session.
Step 3: Post-plunge movement for continued caloric burn
- Once you’re out of the cold water (and have potentially stood in the cold for a few minutes for extra shivering), engage in light exercises like bodyweight squats, lunges, or brisk walking for 3-5 minutes.
- This movement aids circulation, enhances metabolic activity, and promotes a smooth recovery from cold exposure.
Why move?
Combining cold exposure with movement amplifies metabolic benefits, as the body continues to burn calories to generate heat while restoring homeostasis.
Extra tips for fat loss in females: plunging on your cycle
Embracing your cycle as a tool, not a hurdle, can transform the way you approach cold exposure to unlock greater benefits. During the latter half of the follicular phase leading to ovulation, rising estrogen levels make the body more efficient at generating heat through thermogenesis. This is the ideal time for longer, colder immersions to maximise fat-burning and metabolic benefits. Check out our full blog post on cold exposure and your cycle here.
The takeaway
The path to a healthier metabolism might just be through icy waters. While CWT supports fat loss and metabolic health, it’s not a magic bullet—your results depend on a combination of healthy eating, exercise, and consistency. Cold plunging is a powerful tool to complement your lifestyle and help unlock your body’s full potential.