Does a cold plunge boost your metabolism?

Cold plunges are often marketed as a way to "torch calories." The reality is more interesting — and more modest. (For the full picture, see our cold exposure guide.)

What does cold do to your metabolism?

When you get cold, your body works to stay warm. It shivers, and it activates brown adipose tissue (brown fat), a type of fat that burns energy to produce heat. Both raise your energy expenditure — but mostly while you're cold and for a short time afterward.

A 2021 study of young men who regularly swam in winter water and used saunas found they had different brown-fat thermoregulation than non-swimmers, including increased cold-induced heat production. It's a fascinating adaptation, but it doesn't translate into meaningful weight loss on its own.

Does cold plunging help with weight loss?

Not in a meaningful way for most people. The extra energy burned during a few minutes of cold water is small compared with what you'd burn walking, and some people eat more after cold exposure. Diet quality, activity and sleep remain the big levers for energy and metabolism.

The strength-training caveat

A 2015 study found that cold-water immersion immediately after strength training reduced long-term gains in muscle size and strength compared with active recovery. If building muscle is a goal, separate plunges from lifting by several hours or plunge on non-strength days.

How to cold plunge safely

• Start with water around 50–59°F (10–15°C) for 30 seconds to 2 minutes.
• Control your breathing; never plunge alone or while intoxicated.
• Rewarm gradually.
• Talk with a clinician first if you have heart disease, high blood pressure, Raynaud's or are pregnant.

New to it? Read the cold plunge beginner's guide.