During the winter months most people make it a point to avoid the cold weather at all costs by staying inside with heat on, but as humans we have evolved physiological responses to deal with these extreme temperatures and adapt accordingly. Not only are our bodies built to adapt, these adaptations from cold exposure may provide many health benefits along the way. 

Cold exposure has been used in the treatment of certain conditions for centuries and is just now becoming popular among people in the healthcare and wellness industries. Exposing the whole body to cold temperatures may also be referred to as whole-body cryotherapy, and is now being monetized in the form of dry cold chambers as well as cold water immersion.

The Benefits: 

The benefits of cold exposure and cryotherapy are likely due to our body's response to the cold. As our "fight or flight" response is activated in response to cold temperatures,  we produce many kinds of different signaling molecules, hormones, and proteins that can have a wide variety of effects from decreasing inflammation to burning fat. 

Cold Exposure Increases Calorie Burning:

One type of fat in the body is particularly responsible for regulating temperature and using calories to give off heat. This type of fat is known as brown adipose tissue or "brown fat". It has been shown that when exposed to cold temperatures, brown fat activity is increased leading to a higher metabolic rate and more calories burned for heat to allow the body to combat extreme temperature change (1)

Another way that cold exposure increases metabolic rate is through the activation of muscle. Muscle activation occurs as a response to short-term cold exposure and manifests in the form of shivering as a way for the body to respond and generate heat. The shivering in response to cold has been shown to burn calories at a greater rate than brown fat activation and may be the primary mechanism behind the fat burning seen with cold exposure (2). 

In addition to these two calorie-burning responses, signaling from the body's "fight or flight" system may also play a role in fat burning as a response to cold stress. Activation of this response, known as the sympathetic response, causes many chemicals and hormones to be released that stimulate increased fat burning (2). 

Cold Exposure Decreases Inflammation and Improves Inflammatory Joint Conditions:

Cold stress in the form of whole-body cryotherapy has been shown to lower biomarkers associated with inflammation like IL-6 and TNF-alpha (3). It also has been shown to decrease the temperature in-between joints and subsequently decrease damage done within the joint by inflammatory chemicals (4). Due to these effects it has been a common treatment used to decrease inflammation as well as supplement the rehabilitation of patients with rheumatoid arthritis and other inflammatory conditions (3). 

Cold Exposure May Enhance Recovery After Exercise:

Exposure to cold after exercise may theoretically speed recovery time by decreasing the inflammatory response caused by exercise . There is some data suggesting that short-term exposure to extreme cold conditions may result in improved recovery of strength, less pain, and decreased muscle swelling (4). Although research on cold exposure and exercise recovery demonstrates different effects on various populations, the suppression of the immediate inflammatory response to exercise seems to have some impact on recovery. 

One study examined the effects of short-term (3min) extreme cold exposure (-110º C) on athlete's recovery after exercise. It found that this form of whole body cold exposure improved recovery from high-intensity exercise, which could likely be attributed to improved oxygen delivery and reduction of strain placed on the cardiovascular system (5).

Cold Exposure Facilitates Sleep:

Temperature has been shown to be a very important regulator of sleep and sleep cycles. As the day goes on your body naturally decreases temperature to initiate sleep. Cooling the room to between 60-68º F at night may help signal to your body and sleep cycle that it is time for bed. 

How Can I Benefit?

It may be beneficial to take advantage of the cold weather during winter months by spending some time outside. This can be a natural way to receive the benefits of cold stress and also allow for enjoyable winter activities. Another way to benefit from the cold is by using cryotherapy in the form of a cryotherapy chamber, cold water immersion, or even cold showers. All of these forms of cold exposure can allow our natural primal responses to kick in and provide some major benefits along the way.