Josh Atkins is making an argument that sounds simple but contains a genuinely important distinction: heat and cold exposure are not habits to build, they're protocols to deploy. That framing matters. It shifts you from "I do cold plunges" as an identity statement to "I'm using cold for this specific purpose today." The difference in outcome is significant.
The core claim here is about intentionality. Deliberate exposure — the word deliberate carrying real weight — means you're not just tolerating temperature stress. You're engineering a physiological response toward a defined end. Recovery, mood regulation, cardiovascular adaptation, thermal resilience. Each protocol serves a different master.
The dinorphin-endorphin cascade Josh describes is one of the more fascinating pieces of neurochemistry in this space. Dinorphins — the discomfort signal — don't just make you want to quit. They sensitize your mu opioid receptors, which means the endorphin release that follows feels proportionally larger. Push through the discomfort, and joy hits harder afterward. It's not motivational mythology; it's receptor pharmacology.
What's interesting is how well this aligns with the catecholamine research. A 2013 study on whole-body cryostimulation found a 76.2% increase in plasma norepinephrine — a hormone deeply involved in stress response and recovery. The body isn't just reacting to cold. It's launching a coordinated neurochemical cascade. The discomfort is the signal. The adaptation is the reward.
The contrast therapy literature isn't unanimous on mechanisms. A 2023 paper on soft tissue injury management found that the physiological effects of contrast therapy remain "somewhat unclear" — the perceived benefits being largely driven by improved circulation rather than any single well-understood pathway. This is important to hold. The science supports contrast therapy as beneficial, but the precise why is still being mapped.
Josh's thermal regulation tip — cooling the palms and soles rather than the back of the neck — is well-supported by the underlying physiology. Those areas contain AVA (arteriovenous anastomoses), specialized blood vessels that bypass capillaries and allow rapid heat exchange with the core. Cooling there drops your core temperature faster than any ice pack on the neck. Small detail. Large effect.
Start with a clear intention before every session. Not "I'm going to do my cold plunge," but "I'm using cold today to accelerate recovery from yesterday's training" or "I need the neurochemical reset before a difficult afternoon." That specificity changes how you approach the session and what you get from it. Then choose your temperature and duration to match the goal. Recovery? Cooler and longer. Mood regulation? Shorter, colder, with the discomfort deliberately felt and moved through.
Here's what most people miss: the protocols Josh describes — heat first, then cold, cycling deliberately — are essentially a manual override of your autonomic nervous system. Heat drives you into parasympathetic territory: relaxed, dilated, open. Cold yanks you back into sympathetic activation: alert, contracted, primed. Done intentionally, you're training your nervous system to move between states with more efficiency. Over time, that's not just better recovery. That's better emotional regulation, better stress response, better everything. The thermal practice is the vehicle. Nervous system flexibility is the destination.