Cold Plunges & Testosterone: What Nobody Tells You!

Thomas discovered this protocol after battling an elevated PSA of 7 and reading that cold exposure could reduce inflammation. He combined daily ice baths with a ketogenic diet. Four months later, his PSA dropped to 1.8 and his total testosterone rocketed from 700 to 1180 ng/dL. His urologist was convinced he was on TRT and sent him for LH testing; LH came back at 8.9 — extremely high — proving natural production. He replicated the results with his partner Jason, then wrote an article that Joe Rogan read to David Goggins in late 2022. Since then, Thomas has received hundreds of lab reports from men achieving similar gains. The mechanism involves mitochondrial biogenesis and brown fat activation, which improves overall metabolic health and testosterone synthesis in the testes. The key is that the cold must precede the workout; post-workout ice baths for DOMS reduction will suppress testosterone. Women don’t need the exercise component.

Thomas explains that unlike men, women’s testosterone-producing tissues outside the ovaries start working immediately upon cold immersion. This rapid increase in testosterone, dopamine, and oxytocin explains the giggling and affection he’s observed. In his book, he includes four case studies plus women’s experiences. He also notes that post-menopause, declining testosterone contributes to many menopausal symptoms, yet there are no FDA-approved female testosterone protocols. He advocates that clinicians could use cold plunge as a first-line intervention. For couples, the simultaneous release of oxytocin and vasopressin acts like a bonding accelerant, sometimes resolving arguments on the spot.

Thomas explains that when you get into cold, the liver releases glycogen, and white fat cells release free fatty acids to fuel brown fat thermogenesis, causing an immediate ketone spike. This is ideal for entering ketosis or improving metabolic flexibility. Ben shared his post-Thanksgiving pumpkin pie binge — he ate half a pie, had no ketones, then did a four-minute ice bath; a few hours later he was back in ketosis. Thomas added that a cold plunge is more effective at controlling post-meal blood sugar than a walk. However, he warns that excessive cold can stimulate appetite due to the body’s drive to replenish energy, so calorie-conscious individuals should log their intake to avoid undoing the benefits.

Thomas notes that magnesium is a cofactor for hundreds of enzymatic reactions and is essential for mitochondrial ATP production. During cold exposure, blood studies show elevated magnesium, which he interprets as release from bone stores to reach brown fat and muscle for non-shivering thermogenesis. Over time, if not replenished, this can lead to bone density loss, consistent with epidemiological data linking chronic cold exposure to osteoporosis. He personally adds various sulfate salts to his Morozco ice bath (magnesium, potassium, copper, zinc sulfates) and doesn’t shower after, allowing transdermal absorption. He explicitly warns against chloride salts due to potential reactions with the ozone purifier. For oral supplementation, he says taking magnesium at night is fine.

Thomas describes Raynaud’s as a feedback loop between psychological fear and physiological vasoconstriction. He likens it to phobia treatment, where someone afraid of spiders first looks at pictures, then observes a terrarium, and eventually handles a spider. The woman he coached was petrified of cold due to painful Raynaud’s attacks, but her daughter with cerebral palsy loved the cold plunge. That emotional motivation gave her the courage to try. They started at warmer temperatures with breathing guidance. By the third session, she was fully submerged with hands in the water at 34°F with no symptoms. Thomas believes the medical advice to ‘stay warm’ reinforces the fear and prevents remission, whereas cold acclimation effectively cures it.

Thomas makes the case that erectile dysfunction is not a standalone issue but the first clinical marker of insulin resistance, driven by dysfunctional endothelial mitochondria that can’t produce enough ATP for nitric oxide synthesis. Cold plunge, by stimulating mitobiogenesis, restores mitochondrial function in endothelial cells, eventually improving erections. He asserts that in his experience, an ice bath is no barrier to an erection with the right partner. Ben candidly admits that his own physiology seems to require a bit of warming up before sex after a cold plunge, but his wife enjoys the contrast sessions as a prelude. Thomas emphasizes that cold is far more effective than red light for generating new mitochondria, though red light can stimulate existing ones.

Thomas stumbled on this effect after using ice baths and keto to tackle an elevated PSA (prostate-specific antigen). His total testosterone rose from 700 to 1180 ng/dL, with LH off the charts, which astounded his urologist. He then tested the protocol on his business partner Jason, who went from mid-500s to mid-900s. Joe Rogan read Thomas’s blog post to David Goggins in December 2022, and since then, men worldwide have sent in their lab reports showing significant testosterone increases. The few non-responders were men on long-term TRT with atrophied testes or on testosterone-suppressing medications. The key hypothesis: cold stimulates mitochondrial biogenesis and brown fat, and when combined with subsequent exercise, the hormonal cascade boosts testosterone synthesis via LH signaling to the testes.

Thomas noticed that women who got into the ice bath would experience a rapid shift in mood — within 60–90 seconds they’d start smiling and giggling, and by two and a half minutes they’d become playfully affectionate (‘randy’). He attributes this to the immediate activation of secondary testosterone-producing tissues. The catharsis of cold water also releases oxytocin and vasopressin, creating bonding experiences between partners. He and a woman he was dating once entered an ice bath in the middle of a heated argument; after two minutes they were making out, and the videographer had to tell them to stop. Thomas speculates that the neurotransmitter and hormonal surge can erase resentment and foster attachment. He advocates that clinicians consider cold plunge therapy as a way to safely elevate testosterone in women before resorting to off-label male TRT medications.

Thomas outlines three categories of cortisol research: 1) exogenous cortisol administration studies (irrelevant because endogenous cortisol behaves differently); 2) short-term single-bout studies showing an acute cortisol spike, which is actually helpful for people with PTSD who have chronically low cortisol and don't respond well to therapy — raising cortisol prior to therapy improves outcomes; and for those with high cortisol, research from Lithuanian Sports University shows no further spike; 3) longer-term acclimation studies reveal a blunted cortisol response after about two weeks of regular cold exposure. Thus, the cold plunge is a hormetic stressor that ultimately makes you more resilient. Thomas accuses social media influencers of inventing pseudo-medical terms for engagement, while he invites critics to ‘show me your lab reports.’

Thomas explains that only 1% of total body magnesium is in the blood; most is in bones and muscles. During cold exposure, increased blood magnesium is observed, likely because it’s mobilized from bones to support non-shivering thermogenesis in brown fat and muscle mitochondria. Over time, if you practice daily cold plunging without supplementing, you could deplete bone magnesium, potentially leading to osteoporosis. He cites epidemiological data showing higher rates of bone abnormalities in populations with long-term chronic cold exposure. He recommends oral magnesium supplementation, e.g., taking it at night. He personally also adds Epsom salts (magnesium sulfate) to his Morozco ice bath and doesn’t shower afterwards, allowing transdermal absorption, but cautions against chloride salts because they interact with ozone sanitation systems.

Thomas describes Raynaud’s as not just a vascular phenomenon but a conditioned response akin to a phobia. He uses stress exposure therapy (stress inoculation) principles: gradually expose the person to cold in a safe, supported environment until acclimation occurs. He worked with a woman who suffered severe Raynaud’s attacks and was terrified of cold water. Her 9-year-old daughter, who has cerebral palsy and limited sensation, enthusiastically ice bathed and asked her mom to join. That psychological motivation pushed the woman to start at warmer temperatures with breathing guidance. By her third session, she was fully immersed at 34°F with hands in the water — no Raynaud’s symptoms at all. Thomas emphasizes having a supportive coach and a psychological reason (like doing it for her daughter) to overcome the initial fear, which breaks the cycle.