Dopamine rose 250 percent and that was not the point
 
The hashtag #coldplunge has passed one billion views on TikTok. The tubs alone are a $415 million market in 2026. Every morning another woman films herself climbing into ice-cold water and gasping.
She is doing something Shinto practitioners in Japan have done for at least 1,300 years. They called it misogi. They did not film it. But they did something she almost never does: they named what the water was supposed to wash off.
 01 
 
What misogi is
 
Misogi is the Shinto practice of purifying body and mind in cold water. A waterfall, a river, the open sea. The word means “to wash away impurity.”
The origin story is in the Kojiki, Japan’s oldest surviving chronicle, written in 712 CE. The god Izanagi descends to Yomi, the land of the dead, to find his wife Izanami. What he sees there horrifies him. He flees. When he reaches the surface, he walks into the river at Tachibana in Hyūga province. He washes every trace of that world off his body.
From his left eye, the sun goddess Amaterasu was born. From his right eye, the moon god Tsukuyomi. From his nose, the storm god Susanoo. The three most important deities in the Shinto world came from a single act of washing something off.
What the practice looks like.
The practitioner dresses in white. She stands at the edge of a waterfall or enters a river. Before the water touches her, she names what she is releasing. She chants. She steps in. She stays until the prayer is finished. At Shirayama-Hime Shrine near Kanazawa, established in 91 BCE, visitors still perform misogi in a cold pool fed by Mount Hakusan. The priests guide them through the words and the posture.
The Manyoshu, Japan’s oldest poetry collection, compiled around 759 CE, uses misogi as an ordinary word. By then the practice had already moved from myth into daily life.
What the cold plunge is missing.
The cold is not the point. The naming is the point. Misogi begins with a statement: I am washing this off. The cold is the vehicle. Without the naming, you get the dopamine spike but not the direction.
A 2000 study immersed 10 men in 14°C water for one hour. Their dopamine and norepinephrine — the chemicals behind drive and focus — rose by multiples, not small amounts. The body responds to cold whether or not you name anything. But misogi says: the body’s response is not the goal. The goal is deciding what you put down before you step in.
How to do a version of this tonight.
You do not need a waterfall or a tub.
1.End your shower on cold. Or run a cold bath.
2.Before you turn the dial, say one sentence out loud. Name the thing you are putting down. The comparison. The scroll. The yes that should have been a no.
3.Step in. Count to thirty.
4.Step out. Do not pick it back up.
The cold makes the moment memorable. The sentence makes it specific. That is why misogi has lasted 1,300 years.
 02 
 
Where it goes wrong
 
She skips the naming.
She gets in the cold water without deciding what the cold is for. She films the gasp, posts the clip, and feels the dopamine. But she never says what she is putting down. Tomorrow she picks it right back up.
She makes it extreme.
Two-minute ice bath becomes ten. Ten becomes twenty. The practice gets competitive. In misogi, the duration does not matter. The priests at Shirayama-Hime Shrine do not track minutes. They track whether you completed the prayer.
She treats the body like a project instead of a home.
She optimizes her water temperature and her breath count. She tracks every session. The Shinto framing is the opposite. The body is not a machine to be tuned. It is a dwelling to be cleared. You do not upgrade a shrine. You sweep it.
 03 
 
What we’re seeing
 
The dopamine spike is documented.
Researchers immersed 10 men in 14°C water for one hour. Peripheral dopamine rose 250 percent. Norepinephrine rose 530 percent. The effect lasted hours after they got out.
Source: Šrámek et al., European Journal of Applied Physiology, 2000
Five minutes in cold water changed the brain scan.
Researchers put 33 adults who had never tried cold-water swimming into a 20°C bath for five minutes and scanned their brains before and after. The swimmers reported feeling more alert, more attentive, and less distressed. The scans showed stronger connections between brain regions that handle attention, emotion, and self-control.
Source: University of Portsmouth, Biology (MDPI), 2023
One billion views and counting.
The hashtag #coldplunge has passed one billion views on TikTok. The subcategory “cold plunge women” carries over 144 million posts on its own.
Source: TikTok; HealthyWomen, 2025
 04 
 
What the universe is doing this week
 
Today is the autumn equinox. The sun enters Libra at 8:05 p.m. Eastern. Day and night are equal. From tomorrow, the dark gains ground.
The Harvest Moon arrives Saturday, September 26th, full in Pisces at 12:49 p.m. Eastern. This is the full moon closest to the equinox, the one that gave farmers extra light to finish the season.
The moon tonight is waxing gibbous in Aquarius. Mercury is direct and stays that way until October 24th. In the Chinese calendar, today marks the solar term Qiufen — the Autumn Equinox — the midpoint of the harvest season.
The equinox is the one day the sky is balanced. If you are going to name something and put it down, today is the day.
Your next step:
End your shower on cold tonight. Before you turn the dial, say one sentence out loud: the name of what you are putting down. Count to thirty. Step out. Leave it in the water.
Remember, abundance is your birthright.