Whether it’s ice baths, cold water swimming, or cold showers, the benefits of cold water immersion come from both body and mind finding comfort in the discomfort, relaxing your mind into the experience and letting your body do what it is already able to do is how to do it.
The cold is simply an acute stressor, Wim Hof calls it a teacher that’s merciless and righteous. It teaches us through the stress it imposes onto the body and onto the mind. That stress triggers a cascade of biochemical responses inside of us that literally builds us back stronger. How so?
Cold water is a hormetic stressor
The cold is an acute, hormetic stressor. This is very different to the chronic stress of problems at work, financial worries or family pressures. Those stresses can build slowly over years and can lead to chronic issues, both mental and physical, whereas as hormetic stress is a short-lived and intense. It’s the kind of stress that if suffered for prolonged periods would kill us. Another example of hormetic stress is physical exercise. In short bursts over several weeks we notice an improved tolerance, we adapt and even feel good whilst undertaking the stress. Today you may run 1 mile and feel shattered, in several months it’s 10 and you’re exhilarated. Ice baths and cold water exposure work in a similar way, the benefits are realised through revisiting the stressor and thus adapting to it, so let’s dig into them.
The benefits of ice baths, cold showers & wild swimming
- Cardiovascular strengthening – The cold is a serious cardiovascular workout and it’s useful to imagine it this way, it’s a training. The cold triggers vasoconstriction and limiting the blood supply to our limbs and digits, all done to retain core body temperature. Noradrenaline (also called Norephinephrine) is released on contact with the cold – an immediate increase around 530%. This provides a cardiovascular workout for 65,000 miles of capillaries, veins and arteries in the body, imagine all the barely used smooth vascular muscle hidden inside of all that amazing tubing. The tiny muscles contract and release as we adapt to acute cold exposure, moving the blood around.
- Train your body to be a fat burner – Thermogenesis is the body’s process to make you warm. Whereas heat production through shivering is a first move for the body, because it’s a fast way to increase heat through burning glucose in muscle tissue, it doesn’t bear a benefit as such. However, non-shivering thermogenesis – where the body increases our metabolism is fascinating. This is where the body produces heat from metabolic activity, not by contracting muscle tissue. This is achieved by the body metabolising brown fat (brown fat activation) into heat, your body switches on its internal furnace. This is what most of us no longer need to activate in our daily lives. Norephinephrine is again the hormone at play here, triggering your body to turn white fat into brown fat in order to heat up in the moment, whilst also adapting our body over weeks and months of repetition to increase brown fat stores as fuel ready for your next cold encounter. Does the cold help burn fat, yes, and the real benefit is in building up brown fat stores – it’s not a panacea for eating cakes and pizza though! Interesting research here by Susanna Soeberg Phd (Soeberg, et al 2021) [https://www.instagram.com/susanna_soeberg/] shows the just 11 minutes per week (multiple short sessions at temperates below 4°c) is enough to change how your body creates and uses brown fat.
- The cold is anti-imflamaging – Inflammation is a fundamental cause of chronic disease processes, and whilst inflammation can be a good thing when it’s acute, for example muscle and tissue repair, removing dead cells and aiding our bodies to get rid of harmful microorganisms – it’s a bad thing when it’s chronic. Chronic inflammation accumulates and then worsens as we age, and the cold can help here significantly. The hormones noradrenaline, cortisol, and adrenaline are all activated by the cold and act as anti-inflammatory agents. This biochemical response induces a large increase in the circulating levels of the cytokine IL-6, and potentially a mutual release of another cytokine IL-10 (Soeberg, et al 2021) a potent anti-inflammatory agent, IL-6 helps maintain the appropriate balance between pro- and anti-inflammatory factors, critical for resolving a chronic inflammatory response. Important to note that the Soeberg study saw the benefits of hot (sauna) and cold (water swimming) working perfectly together.
- Immune enhancing – a small Dutch study (Buijze et al;, 2016) showed that just a cold shower a day resulted in significant reductions in self-reported sickness compared to those not adopting the habit. A cold shower a day keeps the doctor away.
- The cold presents a net positive effect on mental health – Perhaps the least understood or published benefit is the impact of cold immersion on mental health. And, with the WHO predicting mental health as the world’s number one health challenge by 2030 (it’s currently third) it’s worth understanding how the cold helps. Norephinephrine, acting this time as a neurotransmitter, offers a burst of wakefulness, focus and mood. In fact it has such an impact on our brains that Big Pharma have medications that target it to treat ADHD and depression. Similarly, dopamine enjoys a 250% increase (the equivalent to taking cocaine) providing similar benefits in terms of attention and focus. Combine that with the anti-inflammatory benefit on increasing circulating levels of serotonin in the brain and we can see that a cold dip might just be one of the fastest ways to feel good inside.
Summing this all up, there are short-term acute benefits to the ice baths and cold showers that combine with long-term adaptive benefits for those that practise with the ice baths over months or years. The short term feel good is of course beautiful and the feelings encourage us to come back time and gain for the longer term adaptive benefits to kick in, such as the anti-inflammatory and metabolic, fat burning benefits. Just like an exercise regime might if we’re training to get fit.
How do you get started with cold water immersion?
Slowly and sensibly, the cold is reliably ruthless – but back to Wim Hof, it’s a teacher. Approach it with a smile and with the intention to explore, play and reap the benefits. Use your intuition, trust your body and listen to it. It’s not a race, perhaps start with cold showers or short durations in ice water or outside in nature (the best). Let it guide you, and remember, it won’t be any good if it isn’t any fun. Smile as you dip!