#39: ❄️ Taking the Plunge: Cold Exposure and it’s Health Benefits
#39: ❄️ Taking the Plunge: Cold Exposure and it’s Health Benefits
Protocols for Cold Exposure & the Cold Shock Response
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💬 In this note:
❄️ Taking the Plunge: Cold Exposure and it’s Health Benefits
📚 Four Thousand Weeks
⚡️ The Origins of the Goldfish Cracker
❄️ Taking the Plunge: Cold Exposure and it’s Health Benefits
Cold exposure is often talked about as a strategy to enhance human health. Popularity was skyrocketed by Wim Hof, also known as "The Iceman," for his remarkable ability to withstand extreme cold temperatures.
Techniques for cold exposure range from cold showers and ice baths to cryotherapy sessions in professional facilities. All of these forms of cold exposure introduce various physiological responses in our bodies.
Humans cool two to five times faster when immersed in cold water, compared to when we are exposed to air at the same temperature. This is due to the higher conductive and convective heat loss in water. Water is 25 times more thermally conductive than air.
Therefore cooling down in cold water is extremely effective, even moderately cool water can result in rapid dissipation of the body heat.
Immersion in cold water activates the sympathetic nervous system, the part of our nervous system responsible for responding to dangerous or stressful situations.
Triggering the sympathetic nervous system leads to increased production of neurotransmitters like dopamine, epinephrine and norepinephrine (catecholamines). Activation of these neurotransmitters from the shock of cold exposure can lead to hyperventilation or an increased breathing rate.
Repeated cold exposure and adaptation to the cold will subside the hyperventilation over time.
Cold Exposure and Metabolism
To gain the benefits of cold exposure, you have to activate the “cold shock” response. Which means that the water for your cold plunge should be cold enough to induce discomfort. This discomfort triggers the cold shock response.
Individuals can become more resilient and adapt to the initial shock of the cold water over time. However, it is important to note that the process should not be comfortable, discomfort is an integral part of the experience.
After the cold shock, the body initiates a “non-shivering thermogenesis” process where the body starts to generate heat without shivering in the brown fat.
Brown fat regulates your body temperature in cold temperatures. Brown fat stores energy and burns that energy to regulate your body temperature during cold exposure. It also helps regulate blood sugar and fat metabolism.
Brown fat activates right before you start to shiver and continues to burn energy to keep your body warm while you shiver.
So, we shouldn’t be afraid of shivering. It's OK to shiver in the cold for a bit. But it is important to not stay in the cold water for too long. You want to be uncomfortable, but not push too far because that could lead to hypothermia.
The Drop
Cold exposure experts refer to the decrease in your core body temperature after a cold immersion as “The Drop.”
When you get into the cold water, all of your blood vessels will constrict, this is called vasoconstriction. Your blood vessels constrict because you need to keep the blood in your core to keep your vital organs warm.
Then, after you leave the cold water, the blood vessels open again, and the warm blood flows out of your core to your extremities and the blood gets colder as it spreads the warmth out to the rest of the body, and then it flows back to your core colder.
This decreases the temperature in your core. And the cold exposure experts refer to this as “the drop.”
This drop in core temperature activates shiver which increases your metabolism in order to warm your body back up again.
Deliberate Cold Exposure Protocols
Dr. Susanna Søberg, author of the book “Winter Swimming” which explores various aspects of deliberate cold and hot exposure, discovered that in order to get the benefits from cold exposure, people only need a total of 11 minutes of cold exposure per week.
This is not in one session, but over 2 or 3 separate visits into the cold water. This corresponds to being in the cold water 1 or 2 minutes at a time.
She also recommends cycling between both cold and hot exposure, starting in the cold and ending in the cold. 1 - 2 minutes in the cold water, followed by 10-15 minutes in the sauna, followed by 1 - 2 minutes in the cold.
To get the benefits of hot exposure, the sessions also do not need to be long. Several studies show that the healthy stress occurs after being in the sauna for about 10 minutes per session. It is not recommended to exceed 30 minutes per session. Going beyond that did not show any additional health benefits.
Is a partial cold plunge as effective as a whole body cold plunge?
Yes, any amount of cold exposure on the body can activate brown fat. Dr. Søberg explains that even just a hand in cold water can activate brown fat. Your hands and feet are potent places in your body to get fast activation of your nervous system.
Facial plunges can be effective too, however it is important to note that the face does not have as much brown fat as the rest of the body. Brown fat is primarily located around the neck, spinal cord, kidneys, adrenal glands, heart and chest.
Most studies on cold exposure have been done with submersion up to the neck which would expose the parts of the body with the most brown fat to the cold.
Wondering whether or not to dunk your head in the cold water? A Canadian study showed that heat loss differs between submerging up to the neck and also dunking your head. The study found that 11% of body heat is lost when you submerge up to the neck, however when you also dunk your head, heat loss can increase to 36%.
This can bring you closer to hypothermia, can lead to dizziness and less blood flow to the brain.
Cold showers can also activate brown fat, however clinical studies on the benefits of cold showers compared to cold plunges have not been done and is an area that requires more research. Cold plunges are preferable to showers in clinical studies likely because it is harder to create a controlled environment where the water from the shower hits all the participants in the same way.
Is cold exposure good for longevity?
The physiological changes that occur during cold exposure can potentially impact overall health and lifespan.
The activation of the sympathetic nervous system, the cold shock response, and thermogenesis can all increase metabolic activity and lead to health benefits such as improved weight management, better control of blood sugar levels, boost immunity, reducing inflammation and building resilience to stress. All of which can lead to a healthier life.
However, more research directly linking cold exposure to increased lifespan in humans is needed.
📚 Book of the Week
Four Thousand Weeks: Time Management for Mortals by Oliver Burkeman
5 / 5 Stars
If you live to be 80, you will have just over 4000 weeks of lifespan. Burkeman gives a refreshing insight into time and time management which is far from the ever-popular “get everything done” and “hyper productivity” camps of thought.
If you need another reason to learn more about longevity research, if you live to be 100 you’ll get about 5,200 weeks of lifespan. 🙂
⚡️ Check This Out
The Origins of the Goldfish Cracker
I recently had my mind blown that one of my all-time favorite American snacks, the classic Goldfish cracker is not only a snack cracker. But it’s a soup cracker.
It’s right there on the bag. I, and possibly millions of others, have ignored it our whole lives.
Pepperidge Farms claims that goldfish crackers are similar in flavor and texture to soda and oyster crackers, which are typically eaten in soup.
It’s nearly impossible to find Goldfish crackers in Europe nowadays, but their origins come from Switzerland. The first Goldfish crackers were made by a Swiss biscuit-maker. He wanted to make a birthday present for his wife who was a Pisces (whose symbol is the fish).
The results were a golden fish-cracker that he called Goldfish.
Pepperidge Farms founder Margaret Rudkin visited Europe in the 1960s, and loved the crackers so much that she brought them back to the USA.
In 1997, smiles were added to the Goldfish crackers to make them the little cuties we know and love today.
Now, I’m hungry and craving Goldfish. If anyone wants to bring me a supply of Goldfish crackers from the US to Portugal. I’d love you forever.