In Part 1 of our three-part series on cold thermogenesis, we explored the evolutionary argument for why regular cold exposure may be the key to unlocking inner strength, vitality and health.
But the question is, do we have concrete scientific evidence to back up that theory?
After all, one of the reasons why cold thermogenesis is so popular is because of the long list of health benefits often attributed to it. The headliners include fat loss, improved immunity, enhanced mood, better muscle recovery, and more.
Any health seeker’s ears would perk up if they were told they could have all of those benefits — for free — with a daily dip in cold water.
In this post, we'll take the (cold) plunge into the research to examine the alleged physical benefits of cold training, and whether or not there are scientific studies to back them up.
Breaking Down the Benefits of Cold Exposure
We've taken the top four claims made by cold thermo enthusiasts, examined the research, summarized the key findings and shared our takeaways. Ready to dive in? Ok...Let's go!
Cold Exposure Health Benefit 1: Increases Fat Burning
Cold exposure turns us into fat-burning machines by activating Brown Adipose Tissue (BAT or brown fat).
However, while many will promote the fat loss benefits of cold exposure, the cumulative effect on weight loss is probably relatively insignificant compared to other strategies.
In the first study cited, the subjects were immersed in cold water for two and a half hours which resulted in an additional 250 calories being burned. That may seem impressive at first glance, but is roughly the same number of calories you’d burn walking for half that time.
One study reported 1.5 pounds of fat loss with two hours of daily cold exposure over a six week period. Sounds good, right? But to put this in perspective, one can achieve the same results in just two weeks with exercise and diet. Additionally, cold exposure may increase appetite, making it all too easy to eat your way back to a caloric balance.
Cold thermogenesis has indeed been shown to activate brown fat, boost metabolism, and increase total caloric expenditure...To a certain extent. However, it may not be not the most time-efficient (or comfortable) weight loss strategy.
If you want to lose weight, focus on your diet and exercise, and use cold exposure as a bonus. It certainly won’t hurt!
Cold Exposure Health Benefit 2: Boosts the Immune System
Cold exposure can boost the immune system.
A randomized control trial from 2016 showed a correlation between daily cold showers and a reduction of self-reported absence of sickness.
More immune cells in your bloodstream is generally a good thing, but the relationship between the number of immune cells and immune system efficacy has not been thoroughly studied.
Those who claim that cold exposure enhances the immune system often cite the studies done on Wim Hoff and a cohort of his students. The studies showed that cold exposure (in combination with Hof’s breathwork technique) allowed subjects to suppress their primary immune response in the presence of a bacterial endotoxin (dead E. coli).
These findings are impressive and may have implications for the treatment of autoimmune and inflammatory conditions, but more research is needed to prove that cold exposure improves the immune system’s capacity to fight off active infections.
If you want to stock up on immune cells, cold exposure may be beneficial. Furthermore, if you’re looking for potential benefits for autoimmune disease and inflammation, the Wim Hof Method (both the cold exposure and the breathwork) may be worth looking into.
However, more research is needed in order to fully understand the effects of cold exposure on immune system function and to make specific recommendations.
Cold Exposure Health Benefit 3: Improves Mood
Cold exposure elevates mood and mental focus.
The most common self-reported benefit of cold thermogenesis is an improvement in mood and attention. It has been proposed that this is the byproduct of a marked increase in norepinephrine in the brain, which can increase up to fivefold in response to cold exposure.
Norepinephrine is a hormone and neurotransmitter associated with increased mood, attention and focus. An absence of norepinephrine is associated with poor attention, low energy and depression. The strength of the electrical impulses that travel from the nerve endings in the skin to the brain are also thought to have an antidepressant effect.
In sum, there is a strong positive correlation between norepinephrine, mood, and cognitive function. Cold exposure can greatly increase norepinephrine levels, and therefore enhance mood.
If you’re looking to elevate your mood and mental state, cold therapy is likely to be an effective strategy.
When you ask cold thermo diehards what they love most about the experience, they almost always mention mental calmness and increased vigor. This is no surprise considering that one of the strongest physiological responses to the cold is a huge increase in norepinephrine, which mediates mood, attention and other cognitive capacities.
Cold Exposure Health Benefit 4: Accelerates Recovery
Cold exposure improves post-exercise recovery, which allows for better subsequent training sessions and contributes to enhanced performance over time.
After exercise, the body launches an inflammatory response to support tissue repair, followed by an anti-inflammatory response. Cold thermogenesis appears to mitigate the inflammatory response and aid the anti-inflammatory response.
Although this sounds unambiguously good, it may actually be detrimental for those who strength train.
One randomized control trial shows that cold water therapy immediately after strength training blunts hypertrophy and strength adaptations. This suggests the inflammatory response is beneficial for optimal mass and strength gains and therefore shouldn’t be inhibited if strength and mass are primary training goals.
Studies performed with elite runners showed that cold exposure attenuated the regular inflammatory response, aided the anti-inflammatory response and enhanced muscle recovery.
Another notable feature of cold thermogenesis is that it increases mitochondrial biogenesis. Adding mitochondria to muscle cells increases the muscle’s aerobic capacity which may also play a role in the performance enhancements observed in the studies cited.
If strength and size are your primary training goals, the research suggests that you should refrain from using cold exposure to aid recovery, at least immediately after training.
If you’re an endurance athlete or train to improve your cardiovascular fitness, cold thermogenesis is unequivocally beneficial for recovery.
Although more research is needed to fully understand how cold exposure impacts our physiology, the potential benefits include:
- Increased Fat Loss: Cold exposure may be marginally beneficial for weight loss, but not as effective as diet and exercise strategies.
- Boosted Immunity: Cold therapy can enhance the number of immune cells and may be helpful for autoimmune diseases. More research is needed to fully understand these benefits.
- Improved Mood: Blood plasma levels of norepinephrine significantly rise in response to cold thermogenesis, resulting in increased mood, attention and focus.
- Athletic Recovery: Unless you’re training for strength and muscle mass, cold therapy can speed recovery and improve performance.
As you can see, the possible upsides are good enough reasons to give cold training a try, and all you really need is access to a shower!
However alluring these physical benefits are, they don’t fully capture the most important reason why cold exposure is a daily practice worthy of any health-seeker.
Check back for Part 3 to learn more about the mental benefits of cold exposure and how cold training can make you a happier and more resilient human.
Want to give cold training a try? Already have a practice but want some camaraderie and inspiration? Sign up and join Team Kion, Ben Greenfield, and thousands of others for a free 5-day Cold Thermo Challenge starting August 3rd!
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- Jesse Coomer, Wim Hof Method Instructor
- Angi Fletcher, model, triathlete, and biohacker
- Ben Greenfield, New York Times Best Selling Author and health and fitness expert
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