Should you quit taking cold showers, using cold water immersion, or icing those sore muscles after a workout?
So, at first glance, it would appear you should probably throw your ice buckets in the trash bucket!
Should You Stop Doing Cold Therapy?
However, there are two problems here.
The first problem is that the subjects weren’t working very hard.
Let’s face it: wrist flexor exhaustion by working out your wrists three times a week? Twice a week strength training sessions with three full days of recovery between sessions? A bout of single leg strength training exercises?
None of these activities in a lab surrounded by scientists in white lab coats quite reflect what, say, a professional Tour de France cyclist might experience during a brutal multi-day stage race with over five hours each day spend cranking out more wattage than the average person rides in an entire year of bicycling, or what an Ironman triathlete might experience during 10 hours of redlining their body in the heat, what a football player might experience during intense two-a-day practice sessions during a hot and humid football season, or what a bodybuilder might experience when visiting the gym one to three times a day to completely exhaust multiple body parts.
In other words, in the same way that many antioxidant studies will say that “antioxidants blunt the training response”, but really don’t put participants through very hard training at all, icing studies that use a relatively minimal amount of exercise to argue that icing and cold water immersion doesn’t work simply do not, in my opinion, translate into real world environments for hard-charging athletes and exercise enthusiasts.
But, let’s assume for a moment that icing or cold water immersion really does blunt the training response, and inhibit strength, muscle building, or recovery. These new studies still ignore the host of other benefits you can get from ice and cold that go way beyond bigger biceps. Here are just a few examples (with a full list of scientific references and studies at the end of this article):
-Formation of brown fat
Brown fat, or brown adipose tissue (BAT) is a special kind of fat found in most mammals. When you get cold, brown fat “turns on” and burns off your regular fat on your hips, stomach, legs, etc., in order to generate heat. Basically, brown fat burns glucose and free fatty acids to generate heat during cold stress.
One reason for this is because the hormone irisin is released from muscle tissue exposed to cold temperature. Irisin is involved in the “browning” of white fat (storage adipose tissue) into brown fat. Irisin also lowers myostatin, which (ironically, in light of these new studies suggesting cold inhibits muscle growth) actually allows for greater muscle growth. Irisin has also been shown to function in neuroprotection of brain tissue, and to kill certain types of cancer cells, including breast cancer tissue. Irisin has even been shown to lengthen DNA telomeres, the chromosomes on the ends of DNA strands which shorten as we age, thus potentially promoting longevity.
-Increase in mitochondrial density
Mitochondria are components in nearly all living cells, and often called the “power plants” of cells. Cold thermogenesis directly increase mitochondrial activity and efficiency in several ways. As you’ve already learned, the mitochondria in brown fat (brown adipose tissue) is upregulated in response to cold stress, which burns up extra
This same response also occurs in your muscles, via a process called “skeletal muscle uncoupling,” in which your muscles burn glucose and fats to generate heat in response to cold stress. The hormone adiponectin, which you’ll learn more about in a moment, also increases mitochondrial biogenesis, which increases both the number and efficiency of mitochondria within your cells, and improves your capacity to burn fuel during cold stress, exercise, and daily life.
-Increase in metabolic rate
Your body must burn calories and fat to keep your temperature at 98.6 degrees Fahrenheit. In addition to various hormonal changes that increase metabolism, fat burning, and muscle building, you simply burn a significant number of extra calories when you include practices like keeping the room temperature cold, or a weekly 20-45 minute cold bath or a daily morning and evening cold shower.