Back in October, I shared my 8 Tips For Avoiding Sickness. Then in January, I narrowed it down to what I felt were the three most important in the post Fighting Sickness Ninja Style. After years of getting colds, I was sick and tired of being sick and tired, so I researched how I could boost my immune system. It has now been almost 18 months since my last cold.

Because of my success, I assumed I had figured out why I had defeated the common cold. Turns out there was something I overlooked.

Yesterday I was researching something else when I stumbled on a study that showed that cold water exposure boosts your immunity. This is the exact opposite of conventional wisdom which has people running for sweaters at the slightest breeze. You’ll catch a cold! Nonsense. Your body will release cytokines, which are hormone like substances that trigger other hormones that boost immune function. From the study Immune system of cold-exposed and cold-adapted humans:

It was concluded that the stress-inducing noninfectious stimuli, such as repeated cold water immersions, which increased metabolic rate due to shivering the elevated blood concentrations of catecholamines, activated the immune system to a slight extent.

New readers are probably wondering how this study on cold water exposure could have prevented me from getting sick. Starting last fall, I began experimenting with cold weather exposure. My goal was to quickly acclimate to colder temperatures (I moved to Seattle from San Diego) and possibly burn body fat via activating BAT (brown adipose tissue). Later I learned about the possible positive effects cold temperatures can have on testosterone. More testosterone can result in more muscle, which will increase metabolism. For background, I refer you to these posts.

Since winter ended, at the end of every shower, I turn the hot water to cold and rinse for about 1-2 minutes. If you decide to try this, here is my advice:

  • Breathe calmly. You don’t want a heart attack.
  • Start by aiming the water at the feet and then move to the legs and arms.
  • Eventually move the cold water to the shoulder blades. The shoulder blades is where the highest concentration of BAT is.
  • I don’t see a reason to aim cold water at your chest.
  • Start with moderately cold water and as the weeks go by, go colder.

I think it is time for a cold temperature exposure scorecard.

  • Fast Acclimation – The body will adapt quickly to colder temperatures. Resist the urge to be toasty warm all the time. The body will up regulate your comfort zone. Reduce layers. A little cold weather will toughen you up. Quit babying your body.
  • Fat Loss – Infants are born with high concentrations of Brown Adipose Tissue (BAT). This allows them to generate heat without movement. Unlike jogging this produces no free radicals. Recent studies are showing BAT may be activated in adults for fat loss.
  • Muscle Growth – As I discussed in the post Can Cold Weather Exposure Increase Muscle Growth?
  • Improved Immune Function – The topic of this post.
  • Save Money – A minor point, but worth mentioning. Short-sleeved shirts cost less than long-sleeved shirts. Light jackets cost less than winter coats.

Seems the only downside to cold temperature exposure is short term uncomfort.