GIRL, YOU NEED A COLD SHOWER!

EVERYONE FROM ATHLETES TO CELEBRITIES SEEMS TO BE TAKING COLD SHOWERS OR ICY SWIMS. WE ARE ALL FOR A NEW HEALTH TREND, BUT WE WANTED TO TAKE A LOOK AT THE SCIENCE BEFORE WE JUMPED IN AND GOT OUR FEET WET.   

The inspiration for this article came from our resident cold frog – she is the girl that is always cold, an aspiring swimmer, surfer, and wakeboarder, she desperately loves the beach and ocean but doesn’t enter the water (even in our Aussie summer) for fear of a full body shut down. Her lips and fingertips turn blue as the blood leaves her extremities and rushes to her core in order to sustain her life. It sounds dramatic, but it is all absolutely true. Why, then, would this intelligent, butt-kicking FitHer start having cold showers?! 

So, disclaimer from the outset, there are a lot of, “maybe”, “might”, and “possibly” in the research so far, but what is out there is very interesting and definitely warrants further exploration.  

Once considered an extreme recovery measure only for elite athletes, ice baths and contrast therapy are now commonplace and advocated as legitimate recovery tools for both aspiring and elite performers. Recently however, there has been a push for cold therapy as a positive everyday practice for everyone, regardless of athletic ability or training regime. So, should we all be building cold therapy into our daily routine? Is the occasional cold shower enough? And is it really all it's cracked up to be?

Who’s Idea was the Cold Shower?!

A lot of the recent hype surrounding cold showers and cold swimming comes from ultra-athlete Wim Hof, but hydrotherapy, in various forms, is not a new idea. There is evidence of hydro (water) therapy (healing) dating back to ancient civilisations. It was popularised in the mid-1700s by German theologian Sebastian Knapp. Desperate to continue his studies as a priest, Sebastian managed to survive what should have been a fatal infection of tuberculosis, by taking short dips in the icy waters of the Danube. The self-prescribed therapy fortified his immune system and increased his stamina to the point that his tuberculosis went into remission. A phenomenon previously unheard of. Sebastian went on to complete his studies and dedicate his life to harnessing the healing power of water, plants, and herbs. Sebastian Knapp is now revered as a founder of both Hydrotherapy and Naturopathy.    

Similarly, Dutchman Wim Hof, claims to have used exposure to extreme cold to strengthen his immune and cardiovascular systems, fortifying himself against disease. In 2011, researchers at Radbound University proved that Wim Hof could in fact voluntarily influence his autonomic nervous system. Wim definitely resides on the extreme end of the lifestyle spectrum, but his theories can be applied to all of us, after all we are mostly born with the same basic anatomy and physiology.    

Pump Up the Plumbing

The principal role of the cardiovascular system is to deliver oxygen to, and remove waste from, the tissues. The system consists of a pump – the heart, and a complex system of pipes – veins, arteries, and lymphatics. The heart and blood vessels move blood around the body by changing the pressure inside the vessels. The blood drops off and picks up life-sustaining chemicals and detrimental toxins as it moves around the body. The efficiency of this paradoxically simple but complicated system depends on the health of the pump and vessels doing the work.

Given that the vessels rely on a layer of smooth muscle fibres to contract and relax during these pressure changes, it makes sense that we should maintain these muscles as effectively as possible. Much like the large muscles of the human body, we can “work out” the tiny muscles of the cardiovascular system by adding a small amount of stress to stimulate growth and resilience. Changes in temperature cause blood vessels to contract and relax in the same way a dumbbell curl causes concentric and eccentric stretching of the bicep muscle. 

In extreme cold, the blood vessels of your peripherals contract, sending blood to your vital organs. This is a function of the autonomic nervous system which has evolved over millions of years. A survival mechanism that was essential as little as a few centuries ago, but is now seldom required in the modern age. Once the danger has passed, and hopefully, you have survived, the peripheral vessels are reperfused with warm oxygenated blood. 

This naturally occurring physiological process has been manipulated to create the contrast therapy used widely among athletes of all levels. Movement between hot and cold pools multiple times in a period of 10 minutes to an hour, causes the vessels to contract and dilate repeatedly, taking warm oxygen and nutrient-rich blood to stressed muscles each time, thus increasing the standard rate of recovery. There is some evidence to suggest that regular cold showers can enhance the efficiency of the circulatory system and many proponents report improved, glowing skin as a result. Participants in one study showed increased blow flow to the muscles after taking cold showers post-exercise over a period of four weeks. In good news for those of us not so keen on cold water immersion, researchers found that 15 seconds at a temperature of 12 degrees celsius was enough to see circulatory improvement and there was no further circulatory enhancement in those who had longer cold showers.

Send in the Troops!

There is limited but growing evidence to support the benefits of cold exposure on the immune system. In a study reported in the Journal of Applied Physiology, subjects displayed significant increases in leukocyte stimulation when exposed to cold water after pre-treatment with warm water or exercise. Furthermore, the subjects who were pre-treated with exercise showed a more significant response than other subjects. Leukocytes, (white blood cells) are central to the body's immune response. White blood cells are recruited to attack enemy cells such as viruses, bacteria, and cancer cells.

Research suggests that having leukocytes freely available may enhance and expedite the immune response such that symptoms may not eventuate or are mild at worst. This is an appealing area of research for military personnel and elite winter athletes who are often susceptible to illness, particularly respiratory infection, after prolonged exertion in extremely cold environments.

It has been suggested that regular short exposures to extreme cold may enhance immuno-resilience and fortify the body against disease. Both Wim Hof and Sebastian Knapp provide strong anecdotal evidence of such an adaptation in the human body. Another controlled study, conducted in the Netherlands, found that subjects who took cold showers called in sick less frequently than those who did not.  

Happy Days

There has been some preliminary research into the use of cold therapy in the treatment of mood disorders like anxiety and depression. One clinical trial found that taking cold showers for up to 5 minutes, 2-3 times per week helped relieve the symptoms of depression. It is suggested that the cold water shocks the brainwaves, increasing alertness, clarity, and energy levels. Participants also experienced a rush of endorphins, or the happiness hormone, resulting in enhanced feelings of optimism and well-being. 

Research into alternative therapies for mood disorders remains in its infancy. It is essential to discuss any new therapies with your GP or mental health provider prior to undertaking them.  

Why Not?

While it is usually relatively safe to take a cold shower, some people may need to seek medical advice before getting their feet wet. The sudden rush of cold sends the body into fight-or-flight mode causing a rush of noradrenaline which results in systemic vasoconstriction and an increase in heart rate. In individuals with rate controls disturbances and rarely in otherwise healthy individuals, the sudden increase in heart rate and blood pressure may result in catastrophic failure. In the event of prolonged extreme cold exposure, the heart rate slows, eventually to a rate no longer compatible with life. 

The Cold, Hard Facts:

While the jury is still out, there are definitely more pros than cons.

• 11-15 degrees celsius is considered cold for therapeutic purposes.

• Regular 15-second cold showers have been shown to be sufficient to experience health benefits. 

• Temperature contrast therapy is a useful recovery tool for athletes in specific circumstances and should be undertaken with the guidance of a physiotherapist or exercise physiologist. 

• Ice or cold water immersion is helpful to reduce post-workout soreness as it slows the nerve conduction velocity thus reducing pain.

• Cold water immersion may halt the protein synthesis desirable after a muscle-building session so may in fact be counter-productive. 

• You should NOT start taking cold showers if you suffer a heart condition related to rate or pressure. 

• If nothing else, a burst of cold water at the end of your shower leaves you refreshed, invigorated, and energised.  

A note from the Cold Frog;

My main motivation for taking cold showers was to improve my cold temperature tolerance. I really wanted to spend more time in the ocean but fear of the cold water and my body's reaction to it was holding me back. I was also curious about some of the claims I had heard. To make the transition easier, I started by adding 30 cold seconds to my usual shower. I did this in summer and after a workout so the cold was a relief more than a challenge. Similarly, I started running near the beach, so I was super hot and keen to jump straight in. I hoped that I would gradually develop a strong habit of ocean swimming that I could maintain regardless of the season. 

So far, it appears to be working, after about a week I noticed that I had subconsciously dropped the average temperature of my usual shower and the 30 seconds of just cold was no longer a trauma. (I will acknowledge though, that given I use tank water, the water temp in summer is not super cold). My legs are loving my ocean cool downs after a run and I exit the water happy and refreshed. My cold showers definitely make me feel empowered, like I have conquered something huge, and are undeniably invigorating. As for any systemic changes, well that remains to be seen. I am loving my new habit and fingers crossed, I will keep it up into the cooler months – watch this space.