Convincing evidence that cold plunge can boost total testosterone in both men & women
Summary
Several men and women have documented significant increases in total testosterone after adopting a regular practice of cold plunge therapy.
Some internet influencers seem baffled by these positive results, but the data support the mechanism of steroidogenesis by mitochondria.
There is no definitive clinical trial in either men or women that demonstrates the efficacy of whole-body cold plunge as a therapy for low testosterone.
Mysteries surrounding the benefits of precooling - compared to ice bathing after exercise - persist.
Controversies in cold plunge science
In September 2017, I was a 51-year-old engineering professor with an elevated prostate-specific antigen (PSA) of 7.0 ng/mL and an incidental finding of high-normal total testosterone (736 ng/dL). Instead of following the medical standard of prostate biopsy and risking the resultant allopathic sequelae, I adopted an intermittent ketogenic diet and practiced cold showers.
By December 2017, my PSA had dropped to 1.8 ng/mL.
As the tap water temperature in Phoenix, AZ rose during the Spring of 2018, cold showers became untenable, so I bought a big chest freezer and started daily ice baths. By August, my PSA had dropped further to 1.5 ng/mL, and my testosterone increased to 1180 ng/dL. Moreover, my luteinizing hormone registered an abnormally high 8.9 mIU/mL.
These surprising findings were replicated by Jason Stauffer, my co-founder at Morozko Forge, who boosted his total testosterone from 550 ng/dL at age 40 to 913 ng/dL by 42. So, I wrote about my experiences and a few other similar cases in my article "What Happened to My Testosterone After Using Ice Baths for My Prostate?"
But it wasn't until December 2022 that the question "Do cold baths increase testosterone?" became a trending topic in online searches. That's when Joe Rogan cited my work on his podcast #1906 with David Goggins and explained that he had changed his practice to include pre-cooling exercise because it had worked so well for me.
Since then, the controversy over ice baths for boosting testosterone has increased. Several medical doctors and scientists have published social media posts claiming the opposite of my experience -- even as lab reports and case studies from men and women have come pouring in from readers all over the world corroborating my research.
Case studies in cold plunge for testosterone
During the last two years, I've documented several cases of individuals increasing their testosterone by adopting a cold plunge practice. Now, I'm compiling in this article those that I have verified with personal interviews. Every subject presented here has validated their experiences by sending me their lab reports and permitted me to use their real names to help substantiate this research.
Sean Smiley, 43yo (M)
Sean is a 43-year-old male paramedic and firefighter captain with a history of chronic hypogonadism resulting from a work-related traumatic saddle injury sustained at age 26. Sean's history included unsuccessful attempts at testosterone supplementation that led to adverse effects such as aggression, hypersexuality, and cholestasis, necessitating abrupt discontinuation of testosterone replacement therapy.
At age 39, Sean independently initiated cold water immersion therapy, beginning with pre-exercise cold pool swimming and progressing to ice baths combined with breath work. Remarkably, within 35-45 days, his testosterone levels increased from the low 200s ng/dL to 595 ng/dL. This increase was accompanied by notable improvements in mental health and sexual function, including the resumption of nocturnal tumescence (nighttime erections). Continued adherence to the cold water immersion regimen yielded further improvements, with Sean's testosterone levels reaching 773 ng/dL by July 2024.
Pamela Butler, 60yo (F)
Pamela is a 60-year-old female yoga instructor with a history of total hysterectomy and oophorectomy (removal of ovaries) at age 42, resulting in surgical menopause. Pamela suffered from osteoarthritis and Hashimoto's thyroiditis and reported low testosterone levels. Pamela had been on low-dose hormone replacement therapy (HRT) since surgery and reported medication sensitivity with a preference for non-pharmaceutical interventions. Initial testing on October 5, 2023, showed Pamela's testosterone at 14 ng/dL. In December 2023, Pamela initiated daily cold plunge therapy at 46°F (8°C).
After 40 consecutive days of cold plunge therapy, Pamela reported significant improvements in mental health, mood, anxiety, and osteoarthritis symptoms, allowing discontinuation of steroid injections for back pain. Subsequent testing on May 28, 2024, revealed a dramatic increase in Pamela's testosterone to 168 ng/dL, prompting her endocrinologist to advise discontinuation of testosterone supplementation. Pamela's estradiol levels also increased from 20 pg/mL to 32 pg/mL. Pamela reported no negative or masculinizing effects, instead noting improvements in mental clarity, focus, depression, and anxiety.
Eloise DeSoutter, 32yo (F)
Eloise is a 32-year-old nulliparous (has never given birth) woman with a biological sister diagnosed with polycystic ovary syndrome (PCOS). Eloise initiated a self-directed cold water immersion protocol to assess its impact on her fertility-related health parameters. The intervention spanned four months, with Eloise performing immersions at 2-8°C. Initially, she plunged daily, then reduced to 2-3 times per week.
Pre- and post-intervention measurements recorded on day 3 of her menstrual cycle revealed notable endocrine and anthropometric changes. Eloise's total testosterone increased from 0.6 to 1.1 nmol/L, representing nearly a 2X increase. Her estrogen levels exhibited a 3X increase. Dual-energy X-ray absorptiometry (DEXA) scans indicated a 2% increase in Eloise's total muscle mass and a 2% decrease in total fat mass, with bone mass remaining stable. Eloise reported no additional lifestyle modifications during the study period. Subjective outcomes included enhanced mood, confidence, libido, and energy levels.
David Wootten, 43yo (M)
David is a 43-year-old disabled combat veteran from the 82nd Airborne with a history of PTSD and suicidal ideation. He presented with issues of low energy and erectile dysfunction in 2018 at age 38. Initial laboratory tests revealed David's total testosterone level was 211 ng/dL, leading to a diagnosis of hypogonadism.
David began testosterone replacement therapy (TRT), which elevated his testosterone levels to the 700-800 ng/dL range, resulting in improved energy and libido. He then began biannual blood tests for monitoring. In the summer of 2023, at age 43, David independently started an intense regimen of daily morning ice baths. Subsequent testosterone measurements showed dramatic increases to 1454 ng/dL in December 2023 and 1733 ng/dL in June 2024. Concurrent with the cold water immersion practice, David reported significant improvements in cognitive function, memory, anger management, anxiety, PTSD symptoms, and sexual function.
David Morris, 47yo (M)
David Morris is a 47-year-old male business owner who presented with low energy and was diagnosed with hypogonadism based on initial testosterone levels in the 200 ng/dL range. Testosterone Replacement Therapy (TRT) was initiated at 360 mg/week, resulting in testosterone levels increasing to 800 ng/d.
In November 2023, David began practicing cold plunge therapy before exercise. Subsequent testing revealed an increase in David's testosterone levels to 1100 ng/dL in December 2023 and 1330 ng/dL by March 2024. David also reported increased energy, enhanced libido, and weight loss of approximately 40 lbs. While treating physicians expressed skepticism regarding the causal relationship between cold plunge and testosterone level increases, David is considering discontinuation of TRT due to the observed improvements.
Counter Cases
In addition to the documented case studies showing significant testosterone increases after adopting a regular ice bath practice, two reports of decreases have also reached me.
Lisinopril reduces testosterone
The first is a 35-year-old male military vet who boosted his testosterone from 462 ng/dL in August 2023 to 868 ng/dL in February 2024 by doing 5-minute cold plunges without precooling at 47°F, then progressing to 40°F, often followed by sauna use shortly before sleep. Additionally, he eliminated alcohol intake and reported losing 14 pounds while increasing his muscle mass and physical endurance.
However, when he altered his regimen to precool exercise with cold plunge and tested again about six months later, his testosterone levels dropped by about 150 ng/dL. Unfortunately, he adopted the precooling protocol about the same time he started taking lisinopril for hypertension—without realizing that lisinopril reduces blood serum testosterone levels in men (Koshida et al. 1998). Thus, we can't be certain if his recent drop in total testosterone is due to the precooling or the medication.
Effects of allopurinol
The second case is a middle-aged male MD with total testosterone (before regular cold plunging) measuring ~320 ng/dL, which he considered the "low end of normal." He adopted a precooling protocol consistent with my articles, but after six months, his total testosterone dropped to only ~230 ng/dL.
He reports that he undertakes an intensive exercise regimen, including cardio and resistance, maintains a good diet, limits his alcohol, gets good sleep, is at the "higher end of normal weight," and supplements with Vitamin D. In other words, it sounds like he's doing everything right. So he contacted me wondering why his total testosterone was not responding to the precooling.
Further investigation revealed that during the almost two years that he's been measuring his testosterone, he's also been taking the drug allopurinol to reduce his uric acid levels due to a family history of gout.
It's possible that the allopurinol may be suppressing his total testosterone levels. For example, when Egyptian researchers recruited 84 patients to participate in a controlled trial investigating the effects of allopurinol on testosterone, they discovered a significant decrease in total testosterone in men (Exsander et al. 2013). However, a recent sperm quality study showed no statistically relevant effect of allopurinol on total testosterone in a dozen men after three months (Li et al. 2024). These conflicting findings suggest that the only way to find out what's true for this particular subject is for him to remeasure his T after zeroing out his allopurinol. He's not convinced that taking allopurinol is interfering with his testosterone production, but he's "titrating off" of it anyway.
Do ice baths increase testosterone?
The relationship between ice baths and testosterone is complex and confusing for several reasons:
physiological differences between men and women,
the absence of definitive clinical trials in either sex,
a complex dose-response curve that may indicate the potential for adverse effects at high doses, even while benefits are realized at modest doses,
difficulties in elucidating the mechanisms by which pre-cooling has different effects on men than post-exercise cooling.
Nevertheless, the science of cold plunge therapy for treating low testosterone in men and women is becoming increasingly convincing. As more positive case studies emerge, the evidence supporting ice baths as an effective therapy for low testosterone is clarifying a previously held consensus based on misconceptions.
Mitochondrial mechanisms
Despite documenting these case studies, I've never described the mechanisms by which cold plunge therapy can support testosterone levels. It should come as no surprise that mitochondria are crucial for testosterone synthesis.
Steroidogenesis
Many people know that testosterone is synthesized in the body from cholesterol. That is, without sufficient HDL and LDL cholesterol in the bloodstream, testosterone synthesis suffers. For example, when researchers in Korea studied the blood panel records of thousands of middle-aged men, they discovered that those with low LDL cholesterol also suffered from low total testosterone. Moreover, those with high HDL cholesterol enjoyed the highest levels of total testosterone -- which is precisely what we expect to see when we understand that cholesterol provides the metabolic raw materials for making testosterone (Lee et al. 2023).
However, what most people don't know is that mitochondria perform steroidogenesis (Papadopoulos et al. 2012)—i.e., the conversion of cholesterol to pregnenolone, the steroidal precursor necessary to synthesize testosterone.
This essential role of mitochondria is why mitochondrial health is essential to maintaining healthy testosterone.
Cold + Exercise for Mitochondrial Quality
One of the best indications of mitochondrial function is the triglyceride to HDL cholesterol ratio. Ratios that exceed three (3) indicate poor mitochondrial quality and are associated with insulin resistance, heart disease (Luz et al. 2008), and increased mortality. Ratios less than two (2) are considered normal. For perspective, my triglyceride/HDL ratio usually measures between 0.5 and 0.7, which indicates excellent mitochondrial function.
Because mitochondrial quality is essential to testosterone production, men with high triglyceride to HDL ratios typically have lower testosterone (Chung et al. 2020). In fact, the declines in testosterone characteristic of aging among men in the industrialized world are probably not due to age itself but rather the accumulation of mitochondrial damage associated with a lack of cold exposure, ingestion of seed oils, poor sleep, and poor light hygiene.
It's possible to feel strong and healthy, as measured by capacity for exercise, despite some degree of mitochondrial defect. When that's the case, more exercise is unlikely to stimulate the repair of mitochondria already damaged by poor diet, poor light hygiene, poor sleep, and lack of cold exposure. In my view, the widespread prevalence of low testosterone in young American males is due principally to mitochondrial injury resulting from a myriad of these factors.
As I wrote in Ice Baths for Mitochondrial Therapy, cold plunge therapy is one of the best ways to increase the quality and quantity of your mitochondria. Exercise is probably the second best. However, there is evidence to suggest that exercise and cold together provide the most significant beneficial effect.
For example, when Korean researchers studied the effects of exercise alone, cold water immersion alone, and the combination of cold water + exercise in five-week-old mice, they discovered that the combination promoted increased expression of mitochondrial biogenesis-related genes in muscle and fat tissue (Chung et al. 2017). If the same is true for human beings, then this corroborates the precooling experiences that boosted testosterone in the case studies above.
In extreme cases, the combination of cold water and exercise can put too much stress on mitochondria in ways that temporarily suppress testosterone levels. For example, after a 9-hour dive in 4°C water, 21 male military trainees exhibited a significant reduction in total testosterone levels (Kelly et al. 2022). While the study failed to control for typical, diurnal reductions in testosterone from morning to evening, the findings are consistent with a classic inverted "U" dose-response curve that suggests what can be beneficial in small doses can be harmful at larger doses.
Differences between men & women
Testosterone is the dominant sex hormone in both men & women. That is, even though healthy women have about one-tenth the total testosterone that healthy men do, testosterone levels in healthy women are still 3-4 times the total estrogens (i.e., estrone, estradiol, and estriol). This fact can be confusing because the common understanding is that estrogen dominates the healthy female hormone panel. Compounding the confusion, labs often report estrogen and testosterone in different units, making it seem as if estrogen concentrations are higher. However, when the units are converted for comparison, the higher total testosterone concentration is revealed. Given that little-known knowledge, it stands to reason that testosterone insufficiency has similar effects in both men and women, namely low libido (sexual desire), low motivation and energy, poor body composition (too much fat & too little muscle), depressed mood, and poor musculoskeletal health (Davis & Wahlin-Jacobsen 2013).
Men achieve such high levels of total testosterone via the gonads (testes), which produce more testosterone by far than any other organ. However, in women, only about a third of total testosterone is produced in their gonadal (ovarian) tissue. The rest comes from adrenal glands (Burger 2002), skin (Chen et al. 2002), and fat cells. This may be why an experiment in cold stimulation of the dominant hand showed larger increases in salivary testosterone in young women than in young men (Archey et al. 2019)—because cold stimulation stimulates the adrenals, skin, and fat cells simultaneously.
Paradoxically, some women (but not men) who suffer from metabolic dysfunction develop a condition called polycystic ovarian syndrome (PCOS), in which cysts develop on the ovaries that cause them to overproduce testosterone. In this case, cold plunge therapy can resolve insulin resistance, stimulate mitobiogenesis, restore proper ovarian function, and lower testosterone levels to healthier levels.
Stacy Sims, PhD, has popularized the idea that women respond differently to cold water immersion than men and cautions women against cold plunging at nearly freezing temperatures. She points to a study comparing male and female responses to a cooling blanket that observed women will shiver at warmer temperatures than men and report being more sensitive to cold (Kaikaew et al. 2018). A more comprehensive review suggests that the differences in thermal sensitivity between the sexes are minor and vary throughout the menstrual cycle (Greenfield et al. 2023). Moreover, related studies comparing male and female pain responses to cold stimulation suggest that women acclimate to repeated cold training sessions more quickly than men (Stenning et al. 2007), raising the possibility that the thermal sensitivity differences Sims describes are an artifact of experience, rather than innate physiology.
Sims' advice to start at warmer temperatures could be helpful for women naive to cold plunge—that is, women who are not yet cold acclimated. However, it might not apply to women who are accustomed to cold training. For example, when researchers in the United Kingdom asked more than 1100 women about how cold water swimming affects their menstrual and perimenopausal symptoms, the women reported that they found colder temperatures to be more effective for relief of anxiety, mood swings, irritability, and poor sleep (Pound et al. 2024).
Why does precooling matter in men?
Most of the research regarding cold stimulation, cryotherapy, or cold plunge therapy has been conducted on male athletes. For example, Sakamoto et al. (1991) studied the effects of cold stimulation before exercise, compared to after, in young Japanese men. They discovered that immersing the wrist in cold water for no more than two minutes before a 20-minute session on a bicycle ergometer increased both total testosterone and luteinizing hormone, whereas doing the cold stimulation after the exercise bike suppressed both testosterone and luteinizing hormone. As extraordinary as these findings are, it surprises me that no one has attempted to replicate the study.
There is a much larger body of studies regarding exercise and testosterone in men absent cold exposure (e.g., Riachy et al. 2020). In general, increases in total testosterone have been observed during both intense resistance and endurance exercise, as well as in response to competition (Casto & Edwards 2016). However, these elevated testosterone levels are not sustained for more than a few hours (Dote-Montero et al. 2021). Moreover, in lean individuals, exercise training has no lasting impact on basal testosterone levels, whereas, in obese individuals, it does.
While it is well-established that the long-standing practice of using an ice bath shortly after exercise will suppress testosterone levels and blunt hypertrophy (muscle growth), the fact is that definitive clinical trials regarding precooling and testosterone do not yet exist in either men or women. Moreover, short-term studies like Sakamoto et al. (1991) do not explain changes in basal testosterone levels that could be due to improved mitochondrial function because mitobiogenesis in response to cold stimulation and/or exercise requires days, not minutes.
Over the long term, we would expect any lifestyle change that supports mitochondrial function to increase testosterone, including magnesium supplementation, healthy sun exposure, good sleep habits, and a high-fat ketogenic diet in addition to cold exposure and exercise. However, in the short term, the effects of cold plunging before or after exercise remain somewhat mysterious.
Can cold showers increase testosterone?
In each of the case studies described here, the subjects used whole-body cold plunge therapy, rather than cold showers of cryochambers. Showers are advantageous because they're easy and inexpensive for people living in cold climates. And they are disadvantageous because they cover only part of the body instead of the whole. In Cold Showers vs Ice Baths, I wrote about some of the important differences between whole-body and partial-body cold immersion. For example, researchers in Finland discovered that whole-body will lower heart rate, but partial-body will raise heart rate (Korhonen et al. 2006). That suggests that cold showers and cold plunge will likely have different psychological effects, because the shower will not activate the mammalian dive reflex and strengthen vagal tone in the way that whole-body deliberate cold exposure has been found to do (Mäkinen et al. 2008).
Because testosterone production is both physiological and psychological, it may be that cold showers are less effective for boosting total testosterone than cold plunge or ice bath therapy. Nonetheless, cold showers likely confer some metabolic and mitochondrial benefits that support healthy levels of testosterone, compared to no cold exposure at all. If cold baths are inaccessible to you (e.g., because your home does not have a bathtub), then cold showers are likely a good way to get started on repairing the mitochondrial mechanisms of steroid synthesis.
References
Archey M, Goldey K, Crockett E, Boyette-Davis J. An investigation of the effects of testosterone and behavioral expressions of pain on sex/gender differences in pain perception. Psychological reports. 2019 Jun;122(3):826-40.
Burger HG. Androgen production in women. Fertility and sterility. 2002 Apr 1;77:3-5.
Casto KV, Edwards DA. Testosterone, cortisol, and human competition. Hormones and behavior. 2016 Jun 1;82:21-37.
Chen W, Thiboutot D, Zouboulis CC. Cutaneous androgen metabolism: basic research and clinical perspectives. Journal of Investigative Dermatology. 2002 Nov 1;119(5):992-1007.
Chung N, Park J, Lim K. The effects of exercise and cold exposure on mitochondrial biogenesis in skeletal muscle and white adipose tissue. Journal of exercise nutrition & biochemistry. 2017 Jun 6;21(2):39.
Chung TH, Kwon YJ, Lee YJ. High triglyceride to HDL cholesterol ratio is associated with low testosterone and sex hormone-binding globulin levels in middle-aged and elderly men. The Aging Male. 2020 Apr 2.
Davis SR, Wahlin-Jacobsen S. Testosterone in women—the clinical significance. The lancet Diabetes & endocrinology. 2015 Dec 1;3(12):980-92.
Dote‐Montero M, Carneiro‐Barrera A, Martinez‐Vizcaino V, Ruiz JR, Amaro‐Gahete FJ. Acute effect of HIIT on testosterone and cortisol levels in healthy individuals: A systematic review and meta‐analysis. Scandinavian journal of medicine & science in sports. 2021 Sep;31(9):1722-44.
Eskander EF, Abd-Rabou AA, Ahmed HH. Does Anti-Gout Agent Allopurinol Affect Human Hormones Profile?. Journal of Applied Pharmaceutical Science. 2013 Oct 31;3(10):079-82.
Greenfield AM, Alba BK, Giersch GE, Seeley AD. Sex differences in thermal sensitivity and perception: implications for behavioral and autonomic thermoregulation. Physiology & behavior. 2023 May 1;263:114126.
Kaikaew K, van den Beukel JC, Neggers SJ, Themmen AP, Visser JA, Grefhorst A. Sex difference in cold perception and shivering onset upon gradual cold exposure. Journal of thermal biology. 2018 Oct 1;77:137-44.
Kelly KR, Arrington LJ, Bernards JR, Jensen AE. Prolonged extreme cold water diving and the acute stress response during military dive training. Frontiers in physiology. 2022 Jul 8;13:842612.
Korhonen I. Blood pressure and heart rate responses in men exposed to arm and leg cold pressor tests and whole-body cold exposure. International journal of circumpolar health. 2006 Apr 18;65(2):178-84.
Koshida H, Takeda R, Miyamori I. Lisinopril decreases plasma free testosterone in male hypertensive patients and increases sex hormone binding globulin in female hypertensive patients. Hypertension Research. 1998;21(4):279-82.
Lee JH, Jung HD, Choi JD, Kang JY, Yoo TK, Park YW. Non‐linear association between testosterone and LDL concentrations in men. Andrology. 2023 Sep;11(6):1107-13.
Li C, Wang Y, Mu R, Zhao J, Yao Z, Zhai J, Jin Y, Liu R, Liu D, Hong K, Jiang H. Urate-lowering agents do not have clinically relevant negative effects on sperm quality and reproductive hormones in men with gout: a prospective open-label cohort study. Rheumatology International. 2024 Mar 27:1-9.
Luz PL, Favarato D, Faria-Neto Junior JR, Lemos P, Chagas AC. High ratio of triglycerides to HDL-cholesterol predicts extensive coronary disease. Clinics. 2008;63:427-32.
Mäkinen TM, Mäntysaari M, Pääkkönen T, Jokelainen J, Palinkas LA, Hassi J, Leppäluoto J, Tahvanainen K, Rintamäki H. Autonomic nervous function during whole-body cold exposure before and after cold acclimation. Aviation, space, and environmental medicine. 2008 Sep 1;79(9):875-82.
Miller WL. Steroid hormone synthesis in mitochondria. Molecular and cellular endocrinology. 2013 Oct 15;379(1-2):62-73.
Papadopoulos V, Miller WL. Role of mitochondria in steroidogenesis. Best practice & research Clinical endocrinology & metabolism. 2012 Dec 1;26(6):771-90.
Pound M, Massey H, Roseneil S, Williamson R, Harper CM, Tipton M, Shawe J, Felton M, Harper JC. How do women feel cold water swimming affects their menstrual and perimenopausal symptoms?. Post reproductive health. 2024 Mar;30(1):11-27.
Sakamoto K, Wakabayashi I, Yoshimoto S, Masui H, Katsuno S. Effects of physical exercise and cold stimulation on serum testosterone level in men. Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene). 1991 Jun 15;46(2):635-8.
Stening K, Eriksson O, Wahren L, Berg G, Hammar M, Blomqvist A. Pain sensations to the cold pressor test in normally menstruating women: comparison with men and relation to menstrual phase and serum sex steroid levels. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2007 Oct;293(4):R1711-6.
About the Author
Thomas P. Seager, PhD, is an Associate Professor in the School of Sustainable Engineering at Arizona State University. Seager co-founded the Morozko Forge ice bath company and is an expert in using ice baths to build metabolic and psychological resilience.