The Benefits of Cold-Water Immersion

Article by Lucas Rockwood

The Link Between Brown Fat and Weight Loss

Unlike white fat that serves as energy storage and insulation in the body, brown fat is highly thermogenic and much more prevalent in infants. This unique tissue is mostly distributed around your upper back, collarbone, and chest. Its main role is to help newborns stay warm and avoid shivering in the cold. By adulthood, most of us have just 50 grams of brown fat, but researchers have discovered this can be increased significantly through cold-water immersion. Since brown fat burns calories, can ice baths help with weight loss?

The Different Locations of Bat and Wat

There is limited evidence to suggests that increased brown fat improves metabolic markers and reduces overall body fat percentages (1), but this can be largely attributed to genetic differences. To suggest that cold-water immersion can move the needle enough to change body composition is purely hypothesis, and while certainly plausible, it’s certainly not comparable to the positive outcomes achieved from walking or even mild increases in lean muscle mass. Truly any form of exercise is almost certainly going to have a bigger effect on metabolic health than cold water immersion for fat loss.

The Never Ending Search for the “Burn”

Excess weight is problem with energy balance – more energy consumed than utilized – so there is a forever search in pop health for anything and everything that might increase basal metabolic rate. The false assumption is that a burn deficit will fix the imbalance and weight loss will be effortless. But this almost never works.

Your body is a dynamic organism and rarely lets a calorie deficit rest idle. If you go from a sedentary life to walking daily, your hunger levels rise, and any excess burn is quickly fixed via a couple of extra bites at your next meal. If you fidget all day at work or concentrate for hours playing chess today, you might burn an extra 200 calories. Your body is unlikely to start downsizing. Instead, you’ll crave just a tiny bit more food at your next meal, and homeostasis returns. Remember, if increasing your burn was all that was required for fat loss and body composition, you could simply jump on a treadmill and run until you were thin. But you know it’s not that simple.

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Mental Benefits of Cold-Water Exposure

The real excitement around cold-water immersion should focus on the mental health benefits. They are predictable, remarkable, and long-lasting. Here is what happens.

Sympathetic Nervous System Activation

Plunging into cold water can indeed activate the sympathetic nervous system, which is responsible for the body’s fight-or-flight response. This activation can create a sense of alertness and bring focus to the present moment. The release of norepinephrine, a neurotransmitter associated with arousal, can contribute to this effect.

Happy Neurotransmitters

Cold exposure has been found to trigger the release of endorphins and dopamine, both of which are neurotransmitters associated with feelings of pleasure and happiness. These neurochemicals can provide mood-enhancing effects that may last for hours or even days after exposure.

Circulation Reset

Cold temperatures initially cause vasoconstriction, narrowing of the blood vessels. However, when the body warms up after cold exposure, the blood vessels dilate, resulting in improved circulation. This rebound effect can have positive benefits for both the brain and body, promoting better vascular health.

Is Cold-Water Immersion Worthwhile?

If your goal is to burn fat and improve your metabolic health, cold-water immersion is unlikely to have a meaningful impact and the time invested, compared to the hypothetical benefits, don’t make sense. If your objective is to manage stress, improve your mental health, and improve your circulation, cold-water immersion is a powerful tool that will likely deliver the most benefits with irregular use.

Research

• Brown fat in Inuit population: https://academic.oup.com/mbe/article/34/3/509/2731791
• Brown fat in babies: https://pubmed.ncbi.nlm.nih.gov/29675580/
• Cold water for weight loss: https://www.tandfonline.com/doi/full/10.1080/22423982.2022.2111789