Why You Might Want to Skip the Cold Plunge and Opt for a Dry Sauna Instead

Cold water immersion (CWI), often touted for its many health benefits, has gained popularity in recent years, especially among athletes and wellness enthusiasts. I myself have participated in many a cold plunge a la Wim Hof, with breath-work sessions to accompany them. Off the bat, I want to disclose that I’m not fully knocking them, however, what’s often overlooked is that many of the recommended CWI protocols are based on male physiology and may not be ideal for women (big shocker here!). In fact, the cold plunge might not be as beneficial - or safe - for women as it is for men. So, should women think twice before diving into freezing waters? Here’s why opting for a dry sauna might be a better choice.

Key Cold Stress Response Differences Between Men and Women

There are some key differences between men and women that influence how their bodies respond to cold stress, especially when it comes to cold water immersion. Women generally have a smaller body mass but similar surface area compared to men. This means women have a higher surface area-to-mass ratio, leading to a faster body-cooling rate in cold environments. Women also tend to have more body fat, which provides insulation, but it doesn't necessarily protect against the rapid cooling caused by cold water exposure. Men, on the other hand, typically have more muscle mass, which generates heat through shivering, increasing metabolic output and helping them cope better with cold exposure. It’s always important to remember that women are not small men, despite what much of the scientific research, historically, would like us to believe (and to quote the great Dr. Stacy Sims who inspired this post). 

Hormonal Influences

During the luteal phase of the menstrual cycle (roughly days ~15 through 28-32), women experience a natural increase in body temperature. This is due to the hormone progesterone, which interacts with the hypothalamus, slightly raising metabolic rate and core body temperature. If you track your basal body temperature as a contraceptive method or for fun, you’ll notice your body temperature ticks up after ovulation about ~1 degree Fahrenheit. While this increase can offer some protection against cold stress, it also means women may reach their shivering threshold more quickly during the luteal phase. In fact, research shows that during the luteal phase when the core temperature is higher, women start shivering at a higher body temperature compared to men. This suggests that women may be more sensitive to cold exposure during this time. Interestingly, the increased sensitivity to cold during the luteal phase can reduce the potential benefits of cold exposure, such as brown fat activation, as shivering can cut these effects short in women.

Stress Response

Cold stress triggers the sympathetic nervous system (fight or flight), which can cause severe vasoconstriction (blood flow restriction) and, in some cases, sympathetic nervous system shut-down if the cold is too intense. This can result in an undesirable stress response that outweighs the benefits. While both men and women experience an increase in cortisol (the body’s primary stress hormone) due to cold stress, women may be more vulnerable to the hormonal disruptions it can cause, especially when considering reproductive health.

So, is cold water immersion inherently bad for women? Not necessarily. It may be that the recommended water temperatures for CWI are too cold and adjustments can be made to the temperature to make it more beneficial (and less “stressful”) for women. The recommended water temperatures for CWI (from studies conducted on, largely, men) are often around 46°F-59°F with a mean temperature of 52°F, which may be tolerable for men but could be too cold for women. Women’s athletic performance researcher, Dr. Stacy Sims, suggests that women benefit from cold water immersion when the water temperature is closer to 55°F.

What Does the Research Say?

A 2014 study explored gender-specific responses to cold stress by exposing participants to 57°F (14°C) water for 120 minutes. While this study was designed to assess the impact of cold stress in work environments, we can still draw useful insights for CWI. In this study, women exhibited a stronger insulative response, where the body conserves heat by lowering skin temperature relative to core temperature, compared to men. This is a natural protective mechanism but doesn’t generate additional heat. Men, on the other hand, had a greater metabolic response, with more shivering and non-shivering thermogenesis to generate heat and combat the cold. Thus, men are likely to burn more calories in response to cold whereas women’s bodies prioritize conserving heat by lowering skin temperature relative to core temperature, reducing the energy/calorie expenditure needed to maintain warmth. 

As far as additional benefits go, the men in this study showed greater changes in neuroendocrine (epinephrine) and immune (tumor necrosis factor-α) responses, suggesting they experience more intense overall benefits to cold stress compared to women.

Interestingly, the study did not observe significant differences in cold strain between men and women, but it’s important to note that it didn’t investigate potential menstrual cycle disturbances. Given the cyclical nature of women’s hormones, we can hypothesize that responses might vary throughout the month, particularly during the luteal phase when body temperature is higher and resistance to cold stress is lower.

Cold Exposure: Potential Risks for Women?

While CWI can offer some cardiovascular benefits, such as reducing blood lipids, inflammation, and stress, women may face greater risks compared to men. Cold exposure has been shown to increase cardiovascular strain in women, including elevated heart rate, blood pressure, and more pronounced cold-induced vasodilation (CIVD) in the fingers and toes. These effects can be more extreme in cold environments and pose potential risks, especially for women with underlying heart conditions.

A small 2022 study further highlighted these gender differences. After submerging their hands and feet in cold water, women experienced greater cardiovascular strain (due to the vasoconstriction effects) than men, especially in cold air temperatures, suggesting that women may be more vulnerable to the stressors of cold water immersion. The risks remain minimal, but it warrants a conversation with your body about whether your cold plunges are doing more harm than good. Tap into that intuition and see what your heart is (literally) telling you.

Why Dry Saunas Might Be a Better Option for Women

Anecdotally, I prefer a hot sauna over a cold plunge 9 times out of 10. After doing the research into this post, I began to wonder if this preference was an intuitive message from my body. In other words, a way for my body to tell my mind to opt for a sweat instead of a shiver fest to protect itself from undue stress. In fact, at the time of writing this, I’ve spent 20-30 minutes in the sauna 5 times in the past week (which, coincidentally, is Dr. Rhonda Patrick’s recommendation for sauna exposure). 

Considering the potential risks and discomforts of cold water immersion, women may find dry saunas to be more effective and comfortable options to promote health benefits. Saunas provide many of the same benefits as cold exposure, such as improving cardiovascular health, reducing stress, and promoting recovery, without the undue stress on the body.

Benefits of dry sauna use includes increasing circulation, promoting relaxation by warming up the body gently and encouraging sweating (also detoxifying the body, in turn), boosting metabolism and supporting recovery from exercise without causing the sympathetic nervous system overload that can come from CWI, and boosting mental focus and attention span.  Furthermore, saunas can promote positive cardiovascular changes, anti-aging benefits, and growth-hormone release. Two small studies have shown that regular sauna use can help regulate serum cholesterol and lipoprotein levels in healthy adults, providing cardioprotective effects. In another study, women exposed to 7 x 30 minute saunas over a period of two weeks exhibited reduced cholesterol levels. When looking at the effect on anti-aging, sauna use induces mild heat stress, which activates heat shock proteins (HSPs). These proteins help stabilize cellular structures, repair damaged proteins, and reduce oxidative stress, which may indirectly support telomere preservation and anti-aging effects on the body. Elevated growth hormone (GH) levels from sauna sessions stimulate tissue repair, cellular regeneration, enhance muscle growth/fat metabolism, and promote protein synthesis - processes that may reduce cellular aging and promote overall longevity. GH also enhances IGF-1 (Insulin-Like Growth Factor-1) production, which plays a role in DNA repair, potentially supporting telomere health.

The list of benefits from the sauna go on and on and I highly recommend checking out Dr. Rhonda Patrick’s research for more information on sauna benefits for women AND men, as well as specific protocols. I would be remiss if I didn’t talk about the potential negative effects for sauna use though. Sauna use may contribute to dehydration and electrolyte imbalances - especially in women - so hydrating consistently and replenishing electrolytes is advisable, particularly during the luteal phase.While saunas improve circulation, excessive heat exposure without adequate calcium and vitamin D intake might theoretically exacerbate bone density loss in postmenopausal women. However, this concern is not well-documented! Lastly, extreme heat stress has been suggested to potentially affect hormonal balance. In rare cases, frequent or intense sauna use might temporarily alter the menstrual cycle, particularly in women already experiencing hormonal imbalances. One way to combat this potential effect is to ease into sauna use, starting at the lower end of a protocol (~15-20 minutes) and building from there.

Conclusion

While cold water immersion has its merits, it’s not a one-size-fits-all solution, particularly for women. Given the physiological and hormonal differences between men and women, dry saunas may offer a more balanced approach to recovery and overall wellness. Women should consider their body’s unique needs and opt for therapies that provide the best balance of benefits without unnecessary stress on the body.

If you’re seeking recovery, relaxation, and cardiovascular benefits, consider skipping the cold plunge and warming up in a sauna instead!

Let me know if this works for you!