Ryan Duey's story is compelling precisely because it doesn't start with biohacking. It starts with a motorcycle accident, a brush with mortality, and a man searching for something he couldn't name yet. What he found in cold water wasn't a wellness trend. It was a reset mechanism. The article's core claim is simple: cold immersion doesn't just change your body chemistry — it changes your relationship to discomfort. And that relationship, once changed, transfers everywhere.
The 250% dopamine figure gets the headline, and it should. But Duey's framing is what I keep coming back to: "The plunge is a jungle gym for your nervous system." That's not marketing copy. That's a surprisingly precise description of what's happening physiologically. You're not just cooling your body. You're practicing the skill of regulation under stress.
What Duey describes experientially, the research literature confirms mechanistically. The norepinephrine surge that accompanies cold immersion — which can spike two to three times baseline — is the same cascade that underlies the dopamine effect. Cold triggers your sympathetic nervous system, floods you with adrenaline, and then, as you regulate your breathing and stay present, teaches your prefrontal cortex to override the alarm signal.
This is precisely what Wim Hof demonstrated in the 2014 PNAS study — that through breathwork and cold exposure combined, people could voluntarily modulate their autonomic nervous system response. What was once considered impossible, fixed, involuntary. The human body adapted. And crucially, these adaptations weren't just temporary spikes. Regular practitioners showed sustained changes in baseline inflammatory markers and immune function.
There's strong consensus on the neurochemical effects: dopamine, norepinephrine, and endorphin responses to cold exposure are well-documented. The disagreement lives in the dose and timing questions. Some researchers, including work around post-exercise cold exposure, suggest that cold immersion immediately after strength training may blunt hypertrophic adaptation — essentially cooling the very inflammation that drives muscle growth. The signal that says "get stronger" gets dampened by the same mechanism that reduces soreness.
So the expert debate isn't "does cold exposure work?" It's "work for what, when, and how often?" Performance athletes may want to separate cold plunging from their strength training by several hours. For nervous system training, stress resilience, and mood regulation — the benefits Duey emphasizes — timing relative to exercise matters less. Know what you're optimizing for.
Start at two minutes, not five. Start at cold tap water, not ice water. The adaptation curve is real, and there's no prize for hypothermia. What you're actually training in those first weeks isn't cold tolerance — it's the pause between stimulus and response. The moment where your body screams "get out" and you choose, deliberately, to stay. That pause is the practice. Once you've found it in cold water, you'll start recognizing it everywhere: in a difficult conversation, in a hard decision, in the moment before you check your phone for the fifth time.
Duey mentions float therapy as part of his healing journey alongside cold immersion, and this pairing is more interesting than it might appear. Float tanks remove all external stimulation — silence, darkness, weightlessness. Cold plunging does the opposite: it delivers maximum sensory signal in a compressed window. Together, they bracket the nervous system from both ends. One teaches you to be calm with nothing. The other teaches you to be calm with everything. The underlying skill being trained is identical: equanimity under conditions your nervous system didn't choose. That's not a wellness trend. That's ancient medicine with a modern mechanism.