Sam Maxwell & Kyle Ponton: Does Cold Plunging Really Work? Here’s the Science! | TUH #201

Gary cites exhaustive literature review and says once vasoconstriction is maximal (like a fist), colder doesn't increase constriction. He warns against trying to 'cold adapt' the body, as that leads to physiological changes that reduce longevity (using Eskimos as an example of short life expectancy due to cold adaptation). He advocates cold shocking the body rather than adapting. He also explains the blood shunting hierarchy as evidence of intelligent design.

Gary explains that this reflex is well-documented and can be used to train the nervous system to toggle from stress to calm. He relates it to the hosts' saying 'Don't count if you don't dunk' and to the broader effect observed by his wife's health coach: cold plunge trains the body to manage cortisol and stress better through repeated sympathetic-to-parasympathetic transitions.

Gary adapted his routine after learning that immediate post-exercise cold could reduce hypertrophy. He now cold plunges before hitting the gym, finding it eliminates the need for caffeine or other pre-workouts. He says that doing a hard thing first thing makes the day feel easy. He may optionally do a second plunge later for recovery if desired, but always waits a couple hours.

Gary shares a personal story of being ill during COVID and feeling transformed after a 2.5-hour contrast session. He believes contrast is under-discussed. He also uses a shorter version before bed: brief sauna followed by 30 seconds cold plunge, which he says does not give a massive norepinephrine spike but helps sleep.

Gary and the hosts agree that cold showers are actually harder than a full plunge because of uneven exposure, but they're a good start. Gary suggests using a bathtub with frozen Tupperware blocks as a DIY plunge. The progression is part of the 'get started any way you can' philosophy.

Gary mentions this as a personal practice: he won't get in for a long time, just a short sauna then a quick 30-second cold dunk. He says it doesn't give the massive spike of norepinephrine and dopamine and he sleeps really well on those nights.

Gary acknowledges the study that scared people, explaining that after a heavy lift intended to inflame muscles for growth, immediately cooling deflames the muscle and could hinder gains. He suggests waiting a few hours or—as he now does—using cold exposure prior to exercise to get the norepinephrine spike and focus without caffeine, and then doing a second session later if desired. He emphasizes it's a nuanced discussion, not a blanket ban on post-exercise cold.

Gary details that the reflex is germane to all mammals and is well-documented. When water cools the face, it reduces heart rate and calms the body, enabling a quicker shift to parasympathetic. He ties this to the broader benefit of nervous system training: learning to go from stress to calm quickly, which carries over to managing life stressors. He references Andrew Huberman as first bringing it to his attention, then he verified it himself.

Gary notes that these proteins are stored in the liver and released during cold shock. LIN28A and LIN28B are being studied for their ability to improve insulin sensitivity and decrease insulin resistance, as well as clearing free radical oxidation. He says we're just scratching the surface of their potential. This ties into his broader belief that the body's intelligent design uses cold exposure proactively.

He explains that because you're so physically uncomfortable and focused on breathing, your mind is completely in the present. There is no mental to-do list or distraction. This clarity can last for hours afterward. He ties this to the norepinephrine release that widens vision and sharpens hearing, but the mental effect is the 'eerie form of meditation.' He says this is one of the most underappreciated benefits.

He recounts a trip to Asheville during COVID feeling horrible, and after 2.5 hours of cycling between cold plunge, hot tub, sauna, and steam, he felt amazingly rejuvenated. He categorizes contrast therapy as therapeutic (like a massage) rather than daily recovery, and insists on ending with cold to avoid leaving blood vessels dilated. He personally uses a brief 30-second cold plunge after a short sauna before bed to aid sleep without a massive norepinephrine spike.