From freezing showers to cryotherapy tanks, cold exposure is in vogue amongst health-conscious people. And rightly so; simple practices that can enhance nervous system health, decrease inflammation and promote longevity are rare.
In this article, we will explore the scientific research to uncover the many benefits of getting cold. We will also touch on the best ways to approach cold exposure as, whilst we should embrace the cold, we need to be aware of its power.
What is Cold Therapy?
Cold therapy is not a new invention; it is among man’s earliest medical treatments. The Edwin Smith Papyrus (3500 BC), the most ancient medical text, repeatedly mentioned cold therapy [R].
However, until the late 1980’s, cold exposure remained relatively unappreciated by modern, allopathic medicine [R].
More recently, cold therapy has been increasingly used to prevent or mitigate various types of neurologic injury [R].
Even so, the numerous benefits of cold therapy remain relatively untapped by conventional healthcare practitioners. Hopefully, this article will give you an insight into how you can leverage cold exposure to optimize your health and performance.
Benefits of Cold Exposure
1) Cold Exposure Aids Fat Loss
Location and control of brown adipose tissue [R].
Humans have stores of active brown fat tissue (BAT). Unlike white fat, which stores energy and comprises most body fat, brown fat is active in burning calories and using energy [R].
Indeed, studies show that cold exposure increases BAT activity which leads to increased calorie expenditure. Researchers concluded that frequent cold exposures might be an acceptable and economical way to address the current obesity epidemic [R].
Cold exposure increase shivering and non-shivering thermogenesis. These processes increase calorie expenditure [R].
One study exposed one group of mice to cold temperatures and the other to normal temperatures. The cold-exposed mice ate far more calories but weighed less [R]. This goes against the prevailing view that increased calorie consumption shortens lifespan.
In one study, subjects who were exposed to cold stress had an 80% increase in their metabolism over “warm” levels [R].
If you want to maximize your brown fat levels you should take things with capsinoids, like chili extract. The bitter melon extract also works synergistically with the cold to create more brown fat [R].
2) Cold Exposure Fights Inflammation
Exposure to cold temperatures raises adiponectin, a protein that helps prevent inflammation [R].
Another study found that exercising in the cold reduced the inflammatory response seen in regular temperature environments [R].
This same study found that exercising past a certain time in the cold can actually increase the inflammatory response [R]. The dose is important! More on this below.
3) Cold Exposure Increases Lifespan
A study found that flies lived twice as long when kept at 21°C than 27°C [R].
Similarly, research on worms found that a 5°C drop in temperature increased lifespan by 75% [R].
In 1986, one researcher immersed his lab rats in shallow, cool water for four hours per day. The rats burned so many extra calories that they ate 50% more than control rats. The cold-exposed rats weighed less than the control rats and lived 10% longer [R]. This goes against the prevailing view that increased calorie consumption shortens lifespan.
Another study lowered the core temperature of mice by 0.3 °C (males) and 0.34 °C (females), resulting in an increase in average lifespan of 12 and 20 % respectively [R].
Increased longevity via cold-exposure could be due to hormesis. Hormesis refers to the paradoxical adaptation that makes animals stronger and more efficient if they are exposed to environmental stresses [R].
Other researchers prefer the ‘rate of living hypothesis’. This theory suggests that lower temperature promotes longevity by slowing down the rate of reaction of various metabolic processes. This means fewer by-products of metabolism, such as reactive oxygen species (ROS) [R].
Alternatively, increased longevity from cold exposure may be due to a modulation of genes, such as TRPA-1 and DAF-16 [R].
4) Cold Exposure Strengthens the Nervous System
Wim Hoff (“the ice man”) has been instrumental in showing the world that, through specific training techniques using cold exposure and breathwork, a person is able to control their autonomic nervous system. Before this research was done on Wim, the autonomic nervous system was largely thought to be beyond conscious control.
5) Cold Exposure May Heal Injuries and Speed Recovery
The physiological effects of cold therapy include reductions in blood flow, swelling, inflammation, muscle spasm, and metabolic demand [R].
There is some evidence that ice plus exercise is effective at increasing healing speeds after an ankle sprain or surgery [R].
Cold exposure has a positive effect on muscular enzymes linked to muscle damage (e.g. creatine kinase and lactate dehydrogenase) [R].
One meta-study looked at 360 people who either rested or submerged themselves in cold water after resistance training, cycling or running. 24-minute cold water baths (50-59 F) prevented sore muscles after exercises [R].
6) Cold Exposure Regulates Blood Sugar Levels
Exposure to cold temperatures can increase levels of adiponectin. One study found adiponectin levels increase by 70% after cold exposure. This is important as adiponectin is a protein involved in blood glucose regulation, with low levels found in insulin resistance [R, R].
In rat studies, cold exposure increases glucose uptake in the peripheral tissues – (by enhancing glucose oxidation via insulin-independent pathways). Thus, cold exposure may be beneficial during a fast, as fasting can cause peripheral insulin resistance [R].
Cold exposure can enhance the body’s response to insulin, allowing glucose to be cleared from the blood quicker [R]. A cold bath is one of the quickest ways I have found to lower my blood glucose and increase insulin sensitivity.
7) Cold Exposure Improves Sleep Quality
Natural daily temperature fluctuations are an important regulator of sleep cycles [R].
A Dutch study found that by cooling core body temperatures, participants achieved double the restorative, slow wave sleep [R].
The nonprofit National Sleep Foundation recommends keeping bedroom sleeping temperatures between 60 and 67 degrees F [R].
8) Cold Exposure Strengthens the Immune System
Studies have shown that cold exposure increases natural killer cell count and activity [R].
Cold exposure also increases levels of white blood cells and circulating IL-6.
One study looked at the effects of 6 weeks of cold water immersion (14C for 1hr) on the immune system. Participants had increased levels of IL-6, CD3, CD4, CD8, activated T and B lymphocytes, suggesting a more active immune system [R].
Engaging in exercise before cold exposure enhances the immune stimulating effects of cold therapy.
Increased immune system function could be due to increased levels of adrenaline from cold exposure [R].
9) Cold Exposure Enhances Detox Pathways
Cryotherapy can enhance antioxidant status, allowing the body to deal with free radicals more effectively [R].
10) Cold Reduces Pain
Blasts of cold significantly improve the quality of life for patients suffering from phantom limb pain [R].
Cold compression therapy provides more pain relief than popular, alternative interventions [R].
Cold application alone may be effective in reducing pain associated with migraine attacks [R].
11) Cold Exposure May Increase Bone Health
Some researchers have suggested that age-related decline in bone health is attributable to a loss in brown fat (discussed above). Thus, it stands to reason that regular cold exposure could be an important tool for maintaining bone health as we age [R].
12) Cold Exposure Increases Will Power
This benefit is anecdotal and not backed by scientific research*
Many of my clients and I have noticed a huge increase in will-power from taking regular cold showers.
Nobody wants to get in a cold shower. Getting under freezing cold water every morning trains your brain to do things it doesn’t want to do if the rewards are big enough. This attitude then translates to other areas of your life.
It is best to build up cold exposure gradually.
Start by turning your central heating down, and going for minimally (but legally) clothed walks. Then move on to cold showers. When comfortable with these you might be ready for cold baths and, finally, ice baths.
Cryotherapy (brief exposures to air temperatures below −100°C) is becoming more mainstream and, as a result, more affordable. However, at the moment there is insufficient evidence to suggest it offers advantages over traditional methods of cold exposure [R].
A lot of people like myself don’t have the time to spend hours in the ice bath each day. There are some great hacks to get around this time-constraint:
- ChiliPAD – keeps your mattress cool, helping you get deeper, more restorative sleep
- Cryohelmet – I use this cooling helmet when working on the computer. it’s great for increasing cognitive function.
- FlexiFreeze – this ice vest can be used any time of the day to get the benefits of cold.