It is something we do every day, but the thought of turning the shower to cold is unpalatable for most. Although immersing yourself with cold water may seem a scary prospect (especially in winter!), doing so on a daily basis for just a few minutes carries an array of benefits. These benefits are derived from ‘cold thermogenesis’ (CT), which is just a technical term for heat production brought about via exposure to cold temperatures.
Perhaps the most notable benefit associated with cold showers is brown adipose tissue (BAT) activation. There are two types of fat within the human body: white, and brown. White fat is much more plentiful than brown in the human body, and it stores excess calories. Brown fat, on the other hand, is more akin to skeletal muscle in that it consumes considerable amounts of glycogen and fat when stimulated. It is important to note that leaner people have a greater amount of this ‘good’ fat than their overweight counterparts, and it is mostly situated around the upper back, neck, and collarbone regions.
Immersion of cold water accelerates fat loss through mobilisation of free fatty acids, and enhanced beta oxidation. The mean drop in body temperature initiates thermogenesis, with fat utilisation increased by up to 63% and carbohydrate utilisation by as much as 588%! Metabolism is elevated for several hours afterward, depending on one’s adaptation, meaning a few hundred extra calories burnt throughout the rest of the day. The mechanism to explain activation of BAT is due to the metabolic hormones irisin and FGF21, which may play an imperative role in fighting obesity. Forget high-intensity interval training (HIIT) I say, and make a cold shower a part of your daily routine! Just 2-5 minutes is all that is required, and can be implemented at the end of a warm/hot shower.
An impressive cosmetic benefit of finishing a shower with cold-only is the significant effect it has on smoothing one’s skin. It makes sense that hot water dries our skin, stripping it of its natural oils. I noticed that, within just 2 days, the stubborn patches of dry skin on my face had disappeared. Even lukewarm water can tighten pores and cuticles which will prevent clogging of dirt. Moreover, cold showers serve to diminish dandruff by flattening hair follicles and strengthening their rooting with the scalp.
Despite the continually perpetuated belief that ‘cold temperature exposure causes flu-colds’, the science refutes this misconception. Cold water immersion in fact has been shown to improve one’s immunity and emotional resilience. The stoked metabolism is thought to create additional white blood cells and, perhaps the most important antioxidant, glutathione. This is a crucial adaptive response to frequent oxidative stress, and thus serves to reduce your likelihood of infection or illness. Rather impressively, acute cold exposure also mimics the anti-ageing benefits associated with intermittent fasting and/or caloric restriction, brought about by a down regulation in mTOR pathways. In short, the profound common benefit of all these methodologies is the process of autophagy which cleans out metabolic junk within cells. As such, our cells become hardier and healthier.
Anecdotally, I have found cold showers to significantly improve my mood, even to the point of dancing like a fool while getting dressed post-shower. I even find myself involuntarily giggling and smiling in the aftermath of the slight noradrenaline rush; you will find your energy soar through the roof. No, I am not weird – cold showers genuinely evoke a powerful sense of euphoria! A 2008 study alluded to the potentially analgesic effect cold showers may have for depression sufferers. Although the authors concede that further research was required, these implications are quite remarkable.
For my male readers, you will be encouraged to know that substantial scientific literature suggests a mild boost in testosterone. When the testes are subjected to temperatures that exceed the body’s homeostat of ~37 degrees celsius, specialised leydig cells (which convert cholesterol in to testosterone) become inefficient. Conversely, fertility has been observed at its peak in the colder months from a sample of 6455 males. This is due to elevated luteinising-hormone (LH) and follicle-stimulating hormone (FSH) which act as precursors to testosterone production.
It would be remiss of me not to mention the most frequently touted purpose of cold hydrotherapy; that of speeding up recovery time from delayed onset of muscle soreness (DOMS). Ice baths, and hot-cold showers have been employed by sports teams and athletes for eons, and to great effect. Increased circulation of blood to the outer extremities is known to flush away metabolic waste products while distributing nutrients to the cells. Cold thermogenesis, like exercise, induces arterial & veinous dilation by virtue of the endothelial nitric oxide which lines blood vessels.
So, I hope that this article has inspired you to consider turning the hot shower knob to the left. As you can probably tell, I am a HUGE advocate of cold water immersion and believe the profundity of its benefits go largely unacknowledged. Some consider cold thermogenesis as the true ‘the fountain of youth’. I have only been performing 3-5 minutes of cold showers (after 1-2 minutes of warm water) for the last few months, and trust me when I say it has had an immensely positive effect on me holistically. Turn your music up and allow the cold stream of goodness to fully contact your brown fat zones!
NB: Cold showers may not be a sensible idea for people with:
1. Pre-existing heart conditions (You will notice a much faster heartbeat in the acute stages).
2. High blood pressure (blood pressure and blood glucose are elevated via sympathetic, or ‘fight & flight’, nervous system)
Thanks for reading, and let me know how you go! Remember, it is merely the thought of the cold shower that deters most people…NOT the experience itself.