3 Mistakes That Ruin Your Cold Plunge Benefits

The Huberman Lab Podcast with Susanna Søberg, PhD | DATE

Most people sit in ice baths way too long. Here’s the minimum effective dose, backed by new science.

The Problem With Most Cold Exposure Advice

You’ve heard the claims: Cold plunges boost dopamine. Ice baths torch calories. Winter swimming transforms your metabolism.

But when you actually try it, the advice falls apart.

“Stay in until you’re not cold anymore.”
“Shiver for at least 10 minutes.”
“Go as cold as you can, as long as you can.”

These approaches aren’t just impractical—they’re outdated. Worse, they may actually work against the metabolic benefits you’re trying to achieve.

What if the goal isn’t to endure more cold, but to get out faster?

New research from Danish metabolism expert Dr. Susanna Soberg suggests exactly that. Her landmark 2021 study in Cell Reports Medicine identified the first evidence-based minimum thresholds for deliberate cold exposure—and the findings upend nearly everything you’ve read online.

Here’s what actually works, how little you actually need, and why “ending cold” changes everything.

The Direct Answer: How Much Cold Do You Actually Need?

You need 11 minutes of total cold exposure per week, split into 2–4 sessions, to increase brown fat and improve insulin sensitivity.

That’s it. Not 30 minutes. Not an hour. Eleven minutes.

And here’s the counterintuitive part: Staying in longer doesn’t give you more benefits. It gives you fewer.

Why Most People Get Cold Plunging Wrong

The internet loves extremes. We see people sitting in ice-filled barrels for 20 minutes and assume that’s the goal. It’s not.

Dr. Soberg studied experienced winter swimmers in Copenhagen—people who’d been doing this for years. What she found surprised her.

The veterans weren’t staying in longer. They were getting in and out quickly. One to two minutes per session. Two to three times per week. And they were getting better metabolic results than beginners who tried to gut out longer sessions.

The mistake most people make is treating cold exposure like endurance training. It’s not. It’s interval training for your metabolism.

Common Mistake	Why It Fails
Staying in until you feel “adapted”	The shock stimulus fades; less hormonal response
Warming up immediately afterward	Prevents natural thermogenesis after-drop
Chasing longer durations	Diminishing returns after ~2 minutes; increased recovery need
Using the same temperature every time	Cells stop adapting to novelty

The Soberg Principle: End Cold, Every Time

If you take only one thing from this research, make it this:

Always end your session cold.

This is non-negotiable.

When you finish in a hot shower or sauna, your body doesn’t need to generate its own heat. The metabolism boost stops the moment you warm up externally.

But when you end cold—and force your body to warm itself—you extend the metabolic effect for hours. Your brown fat stays activated. Your muscles continue generating heat. Your norepinephrine levels remain elevated.

Dr. Soberg calls this the “after-drop” benefit. Your core temperature actually continues to fall slightly after you exit the water. That’s not dangerous—it’s the point. That drop forces your body to work.

Ending cold turns a two-minute plunge into a two-hour metabolic workout.

What Is Brown Fat? (And Why You Want More of It)

Brown adipose tissue—brown fat—is your body’s natural heating system. Unlike white fat (storage), brown fat burns energy to create heat.

Think of it as an internal furnace. Every time you expose yourself to cold, that furnace gets stoked. Over weeks and months, the furnace grows. You develop more brown fat cells. The mitochondria inside them multiply. Your body becomes more efficient at generating heat—and burning calories in the process.

Here’s what the research now shows:

Cold exposure activates brown fat within minutes—even just placing a hand in cold water triggers it
Women naturally have more brown fat than men, which may explain different thermal comfort preferences
Brown fat is highly plastic—it grows with regular cold exposure and shrinks when you stop
People with active brown fat clear blood glucose faster and produce less insulin

One subject in Dr. Soberg’s study had no detectable brown fat at all. He couldn’t regulate his temperature. He shivered uncontrollably during mild cooling. His insulin looked like the control group’s, not the winter swimmers’.

Brown fat isn’t niche biology. It’s central to metabolic health.

The 11-Minute Protocol: What Actually Works

Based on Dr. Soberg’s research and subsequent field testing, here’s the evidence-based framework for deliberate cold exposure:

Weekly Target: 11 Minutes Total
Session Length: 1–3 Minutes
Frequency: 2–4 Sessions Per Week
Temperature: Uncomfortably cold but safe (typically 10–15°C / 50–59°F)

That’s it. You don’t need ice. You don’t need a $6,000 plunge. You don’t need to work up to 10-minute sessions.

Method	Effectiveness	Notes
Full immersion (neck down)	Highest	Maximal cold receptor activation
Cold shower	Moderate	Less skin coverage; harder to control temp
Outdoor cold air	Mild	Slower response; requires longer exposure
Face dunk only	Minimal	Good for dive reflex; poor for brown fat

The One Variable You Should Actually Change

Most people obsess over temperature. Is 45°F better than 50°F? Should I add more ice?

Dr. Soberg’s response: Vary it.

The body adapts to consistency. If you use the exact same temperature every time, the stress response diminishes. Your catecholamine release shrinks. The hormetic effect weakens.

Instead, intentionally vary your exposure:
Some days, make it aggressively cold
Other days, take it easier (but still uncomfortable)
Let seasonal changes work for you—colder water in winter, milder in summer
If you use a home plunge, adjust the temperature periodically

The stimulus isn’t cold. It’s change.

What About Heat? The Sauna Component

Dr. Soberg’s study also tracked sauna use. The winter swimmers in her study did 57 minutes of sauna per week, split into 10–15 minute sessions.

This aligns with the massive Finnish sauna cohort studies showing that 4–7 sessions per week of 10–20 minutes correlates with significantly lower cardiovascular mortality.

But here’s the overlooked insight: The combination matters more than either alone.

Cold and heat aren’t opposing therapies. They’re complementary stressors. Alternating between them:

Increases vascular plasticity
Improves skin blood flow regulation
Extends the metabolic activation window
May enhance sleep quality (through core temperature cycling)

If you have access to both, use both. But cold alone still delivers significant benefits.

Why Shivering Isn’t Your Enemy

We’ve been taught to avoid shivering. Get out before you shake. Warm up immediately.

This is exactly backward.

Shivering is not failure. Shivering is the workout.

When you shiver, your muscles contract involuntarily to generate heat. This requires energy—sometimes substantial energy. One study estimated that intense, sustained shivering can increase metabolic rate 5x above baseline.

But more important than the immediate calorie burn: Shivering signals your brown fat to activate. It’s the call-to-action for your internal furnace.

Dr. Soberg’s infrared thermography showed brown fat temperature rising within four minutes of cold exposure. That activation doesn’t happen if you exit before the shiver response engages.

You don’t need to suffer. But you do need to let the process work.

Practical Protocol: How to Start This Week

You don’t need to join a Danish winter swimming club. You don’t need to move to Scandinavia. You don’t need to buy expensive equipment.

Here’s the minimum viable protocol:

Week 1–2: End your regular shower with 30 seconds of cold. Face, chest, back. Breathe through it.
Week 3–4: Extend to 60 seconds. Focus on slowing your breathing. The hyperventilation will subside.
Week 5–6: If accessible, try full immersion. Cold tub, lake, ocean, or plunge. Start with 1 minute. Increase to 2 minutes over several sessions.
Ongoing: 2–4 sessions per week. 1–3 minutes each. Total weekly cold time: 11 minutes.
Always end cold. No warm shower afterward. Let your body heat itself.

Who Should Be Cautious

Cold exposure is a stressor. That’s why it works. But it’s not for everyone in every state.

Higher risk groups:

Children: Smaller body mass means faster core cooling. Limit exposure time significantly.
Small-framed adults: Same principle. You lose heat faster than larger individuals.
Raynaud’s syndrome: Cold triggers extreme vasoconstriction in hands and feet. Keep extremities out of water or use neoprene booties/gloves.
Uncontrolled hypertension: Cold spikes blood pressure acutely. Get medical clearance.
Pregnancy: No safety data on deliberate cold immersion. Shorter, milder exposure only.

When in doubt: Shorter is safer than longer. You cannot “earn” benefits by pushing through danger signs.

Key Takeaways

11 minutes per week is the evidence-based minimum threshold for metabolic benefits
End on cold—never finish with external heat if you want the full after-drop effect
Brown fat is trainable; regular cold exposure increases its volume and activity
Shivering is productive, not a sign to stop
Vary your temperature; consistency reduces the stress response
Women have more brown fat than men and may need slightly different protocols
Sauna adds benefit but isn’t required; 57 minutes per week is the observed threshold
More is not better—beyond 11 minutes cold and ~30 minutes sauna, benefits plateau

The Bottom Line

The cold exposure community has spent years chasing the wrong goal. We thought more time equaled more benefit. We thought adaptation meant staying in longer. We thought warming up immediately was the reward.

Dr. Soberg’s research flips all of it.

The goal isn’t tolerance. The goal is stimulus.

You don’t need to sit in ice for 20 minutes. You don’t need to build up to marathon sessions. You don’t need to suffer.

You need 11 minutes. You need to end cold. And you need to do it consistently.

The rest is just ice.

Here's what you need to put this to action

Capsinoids: Brown Fat Support in a Capsule

Cold water activates brown fat via skin receptors. Capsinoids—non-pungent chili pepper compounds—activate the same metabolic pathway through your gut. The mechanism differs. The destination is the same.

Human studies support this. A 2020 randomized controlled trial in Nutrients found that 9 mg of capsinoids daily for six weeks increased brown fat density by 12.4% and raised resting energy expenditure by 4.3% in overweight adults . The effect is specific to individuals with detectable brown fat; capsinoids essentially “turn up the dial” on your existing furnace. This is not a replacement for cold. It is a separate on-ramp for days you cannot or don’t want to plunge.

Cold Water	Capsinoids
11 min/week	9 mg/day
Immediate effect	4–6 weeks
Skin-mediated	Gut-mediated
Human PET-CT evidence	2020 RCT evidence

Podomline’s recommendation: NOW Cayenne 500 mg

The Cold Plunge Tub to Watch

If you want a true plug-and-play system that arrives with the chiller built-in, the JUGRFIT is engineered to deliver Dr. Søberg’s 37–40°F protocol without a single bag of ice. Its 1050W chiller maintains precise cold, the 121-gallon stitch-bonded tub fits most adults comfortably, and the integrated filtration extends water life between changes.

Podomline’s recommendation: JUGRFIT 121-Gallon System

*The information provided on this site is for general informational and educational purposes only. All content, including articles, guides, and opinions, is not intended to be, and should not be taken as, professional advice.
*Podomline may earn a small commission if you buy through these links—at no extra cost to you. Thank you