What is Cold Exposure?
Cold exposure is a manipulation of thermoregulation in the extreme of reducing temperature, by changing the external temperature cold exposure attempts to achieve certain cellular effects which can be used towards ones health goals.
Thermoregulation techniques are built around the concept of adaptive thermogenesis. The human (adult) body maintains a temperature of 36.4–37.1 °C. Changes below this threshold will cause adaptive changes to maintain range and changes above this threshold will cause changes to counter the change in the opposite.
Meet your New Friend BAT (brown adipose tissue)
When it gets too cold, the body creates heat by shivering. This shivering can multiply our heat production fivefold and hence burn a ton of calories. Which is great, except for one thing: shivering totally sucks. Luckily, once you get accustomed to a colder environment, you stop shivering so much, but you continue burning calories to produce heat. This is known as “non-shivering thermogenesis”. How does this process occur? Through BAT: brown adipose tissue. Whereas normal fat (white adipose tissue) is used for energy storage, brown fat is used for heat production.
Most of our brown fat is located around the shoulder blades and neck. It becomes activated when we’ve been exposed to the cold. One important thing about brown fat is that, whereas it is activated during cold exposure, it is also produced after cold exposure. This doesn’t mean you can develop brown fat after one cold shower, but it does mean that long-duration of cold exposure can build up your brown fat stores (e.g having regular cold showers daily) and a ice bath once a week.
Will Cold Immersion help with Recovery?
The theory behind ice baths or cold therapy is related to the fact that intense exercise causes tiny tears in your muscle fibers. This microscopic muscle damage is actually a goal of exercise as it stimulates muscle cell activity and helps repair the damage and strengthen the muscles. But it is also linked with delayed onset muscle pain which occurs between 24 and 72 hours after exercise.
The ice bath was believed to:
1. Constrict blood vessels and flush waste products, like lactic acid, out of the affected tissues.
2. Decrease metabolic activity and slow down physiological processes.
3. Reduce swelling and tissue breakdown.
Then, with rewarming, the increased blood flow was believed to speed up circulation, and in turn, improve the healing process.
If you are going to try cool or cold water immersion after exercise, don't overdo it. One review of studies found the best routine was 11 to 15 minutes of immersion at a temperature between 11 to 15 degrees Celsius. That should be enough time to get the benefit and avoid the risks.
a b Cannon B, Nedergaard J. Nonshivering thermogenesis and its adequate measurement in metabolic studies.J Exp Biol. (2011)
a b c van Marken Lichtenbelt WD, et al. Individual variation in body temperature and energy expenditure in response to mild cold. Am J Physiol Endocrinol Metab. (2002)
Cannon B, Nedergaard J.Metabolic consequences of the presence or absence of the thermogenic capacity of brown adipose tissue in mice (and probably in humans).Int J Obes (Lond). (2010)