It’s coming to be that time of year when our instinct is to bundle up—But maybe we shouldn’t! Cold shock therapy has been studied for many years and has shown numerous benefits correlated with general health and longevity. Cold exposure has been shown to improve immune response, increase dopamine, improve athletic performance, increase brown adipose tissue (which is the kind of fat you WANT to have), reduce inflammation, and more.
Cold exposure is exactly what it sounds like: allowing your body to be exposed to cold temperatures to achieve a certain physiological response. When we allow our bodies to reduce in temperature it causes many different actions. For example, cold exposure stimulates the release of norepinephrine (Adrenaline or NE), which leads to vasoconstriction, thermogenesis, activation of genes involved in energy metabolism (from fatty acid metabolism to glucose control), immune regulation, and more. This is achieved at ~57°F but has greater benefit at colder temperatures. There are various ways to participate in cold therapy that are effective. Ultimately, the right type of therapy will depend on the goal.
GET COLD TO GET HEALTHY
Some of you may be familiar with Wim Hof, also known as “Iceman” (with good reason). He has carried out many experiments on himself in an effort to demonstrate the benefits of cold exposure. For instance, a study by Radbound University compared one aspect of those who practice Wim Hof cold exposure therapy regularly to those who do not. They found that after exposing both groups to a pathogen, those who practiced regular cold therapy had more robust immune responses and fewer symptoms. Another exploration of cold exposure by Wim Hof showed anti-inflammatory markers increased by 200% and pro-inflammatory markers reduced by 50% (Kox et al 2014). This flu and cold season, get ahead of illness by participating in regular cold therapy!
GET COLD TO STAY YOUNG
It is becoming more well known that inflammation acts to speed up the aging process. Luckily, cold exposure is another intervention to help mitigate that process. A study by Lin et al showed that after only five days of healthy individuals undergoing cold exposure had notable reduction in inflammatory markers (IL-2) and an increase in anti-inflammatory markers (IL-10).
As you may already know, mitochondria are very important when it comes to aging. This is because of their role in energy maintenance and managing reactive oxygen species. Being such hard workers, they must be frequently renewed. Luckily for us, cold exposure stimulates mitochondrial biogenesis (Ihsan, M. et al). This effect has been primarily demonstrated in mitochondria of the skeletal muscle. This allows us to move more at all ages.
Movement is a big contributing factor to our ability to feel young. Unfortunately, arthritis is one of those conditions that slows us down. On the upside, more research is being done regarding non-invasive interventions. Cryotherapy is one of these interventions and it is showing promising results for improvement in pain perception for conditions such as rheumatoid arthritis. A study in 2015 used a variety of cold exposure therapies for RA patients. They assessed pain following the treatment and found that whole body cryotherapy reduced pain, morning stiffness duration, fatigue, improved speed, and function.
GET COLD TO GET SLEEP
Adequate sleep is one of the most valuable components of health, but too many of us are not getting quality sleep! Among the many hacks to improve sleep, lowering your room temperature is an effective one. Sleep expert Dr. Matt Walker has stated in multiple interviews that the key to falling asleep and staying asleep is allowing your body temperature to drop by 2-3°F as this mimics cool nights. The Sleep Foundation recommends setting your bedroom thermostat at 65°F (+/- a few degrees) for adults.
GET COLD TO GET HAPPY
Dopamine is often referred to as our “happy hormone” (although technically it is a neurotransmitter) that correlates, not only to mood but also to movement and planning. It is used to send messages between neurons. It is a neurotransmitter that often gets depleted in the winter months, causing conditions such as seasonal affective disorder. A study investigated the effects of cold water immersion on hormones of young men who were otherwise healthy. They found that dopamine levels increased by 250% when immersed in water at 57°F (Sramek, P. et al). Suggestions to this approach from an anecdotal report include a cold shower (68*F) for two to three minutes followed by gradual increase in temperature performed one to two times daily for weeks or even months (Shevchuk, N.) Next time you’re feeling blue, hop in a cold bathtub to get that happy hormone boost!
GET COLD TO GET SMART
Through the promotion of dopamine release, adrenaline release, and neuronal protein synthesis, cold therapy is a good way to support cognitive functioning. Norepinephrine has been shown to increase mental acuity. A study of healthy women showed an increase in NE levels by 200-300% when undergoing cryofusion at -166°F for two minutes (Leppäluoto, J., et al ). Longer duration (1 hour but can be seen at 20sec with cryotherapy) has an even greater release of adrenaline (Johnson, D. G. et al)
Furthermore, cold shock proteins (proteins conserved for stress) promote protein synthesis at neuronal synapses. This process allows for more robust communication between neurons and regeneration of neurons (Al-Astal, H. et al and Chip, S. et al).
GET COLD TO GET FIT
You may have heard that athletes often take ice baths. This is because cold therapy has been shown to help muscle recovery after exercise as well as reduce body fat. Cold exposure has been shown to specifically increase brown adipose tissue (the kind of fat you WANT to have). BAT is beneficial because it contains greater amounts of mitochondria which increases its oxidation ability. A small study of six men underwent cold exposure of 50*F for two hours five days per week for four weeks. The results showed that BAT increased in metabolic activity by 45% (Blondin et al). This approach is very manageable by the average person.
Dr. Craig Heller, a leading expert in temperature regulation, has long studied the impact of cold on performance. Increased heat tends to reduce performance, so as you work out and increase body temperature your performance is expected to decline. Taking a cold shower prior to anaerobic exercise (such as lifting weights) allows for greater tolerance to increased body temperature and sustained performance. However, it could potentially blunt gains if you take a cold shower within one hour after your workout.
If you are someone whose exercise of choice is endurance, then it may be worthwhile to include cold baths in your regimen as well. As previously mentioned, cold exposure increases our ability to produce new mitochondria. Increasing the number of mitochondria within our muscles allows for greater aerobic capacity, and therefore, they are key for adapting to and improving endurance (Memme, J. et al). This has been demonstrated by a study that had men submerge one leg in cold water for 15 minutes post-exercise. The leg in cold water (but not room temperature leg) had increased levels of proteins correlated with mitochondrial synthesis (Ihsan, M et al). Furthermore, as a quick tip to improve performance you can simply cool your palms mid-workout. Cooling of the palms and soles of the feet during exercise increased endurance duration noted in Dr. Heller’s labs. For this reason, he advises using loose grips when cycling, rowing, skier machine, etc. and also avoiding gloves during workouts.
HOW TO START
- Very cold temperatures (<10*F) should be avoided unless exposure is at a clinic where it is controlled in order to reduce risk for frostbite
- Cryotherapy at a local clinic (consider wearing gloves and socks for whole body cryotherapy)
- Cold water immersion (59*F) or cold showers
- Cold packs to specific areas of the body (joints or muscles)
- Avoid cold exposure for one hour after exercise
- Wim Hof Method app with introduction to cold showers, cold plunges, Cryofusion
- Al-Astal, Heyam I. M., Maram Massad, Manaf AlMatar, and Harith Ekal. “Cellular Functions of RNA-Binding Motif Protein 3 (RBM3): Clues in Hypothermia, Cancer Biology and Apoptosis” Protein & Peptide Letters 23, no. 9 (August 2016): 828–35. https://doi.org/10.2174/0929866523666160628090340.
- Blondin, Denis P., et al. “Increased Brown Adipose Tissue Oxidative Capacity in Cold-Acclimated Humans.” The Journal of Clinical Endocrinology & Metabolism, vol. 99, no. 3, 2014, doi:10.1210/jc.2013-3901.
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- Kox, M, et al. “0026. Voluntary Activation of the Sympathetic Nervous System and Attenuation of the Innate Immune Response in Humans.” Intensive Care Medicine Experimental, vol. 2, no. Suppl 1, 2014, https://doi.org/10.1186/2197-425x-2-s1-o2.
- Leppäluoto, J., T. Westerlund, P. Huttunen, J. Oksa, J. Smolander, B. Dugué, and M. Mikkelsson. “Effects of long-term whole-body cold exposures on plasma concentrations of ACTH, beta-endorphin, cortisol, catecholamines and cytokines in healthy females” Scandinavian Journal of Clinical and Laboratory Investigation 68, no. 2 (January 2008): 145–53. https://doi.org/10.1080/00365510701516350.
- Lin, Yen-Ju, Martina Anzaghe, and Stefan Schülke. “Update on the Pathomechanism, Diagnosis, and Treatment Options for Rheumatoid Arthritis” Cells 9, no. 4 (April 2020): 880. https://doi.org/10.3390/cells9040880.
- Memme, Jonathan M., Avigail T. Erlich, Geetika Phukan, and David A. Hood. “Exercise and mitochondrial health” The Journal of Physiology 599, no. 3 (December 2019): 803–17. https://doi.org/10.1113/jp278853.
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