Brrrr… Just thinking of a plunge into ice-cold water is enough to make us shudder, and it might seem an activity for adrenaline junkies.
Now, scientists say a dip into a tub of ice-cold water has numerous positive effects on our brain.
Historically speaking, across the world, cold water baths are known to many regions and cultures.
They have been a part of Indian traditions; a favoured recreation of the Scandinavians; and in ancient Rome, frigidaria or the cold rooms were the last link in a chain of bathing chambers.
Ancient Greek physician Hippocrates observed that hydrotherapy with cold water had physiological benefits. Today, sports experts recommend that athletes plunge themselves into a tub of ice water to ease sore muscles.
The benefits of a cold water dip extend beyond muscle relief, say scientists. It has been found to improve immunity, focus and elevate the mood.
Dutch endurance athlete Wim Hof, famously known as the Iceman, played a key role in popularising the mental advantages of enduring frigid temperatures. His feats set off a series of studies to understand how the body and mind react when exposed to cold temperatures.
What is cold water immersion therapy?
An ice bath became a daily routine for former cricketer and entrepreneur David Mathias. Soon, he noticed that the icy waters relieved sore muscles and became a source of motivation, dopamine boost and focus for the day. Drawing from his experience, he delved into the science of the technique, which seemed to relieve stress and anxiety, giving him an additional boost for the day.
Cold immersion therapy requires a person to take dip neck deep in cold water: either in water of 4-8 degrees Celsius for four to eight minutes; or in water of 10-15 degrees Celsius for 10 to 15 minutes. The time and temperature differ from person to person and are best practised under the guidance of a professional.
Mathias has identified the best conditions that work for him and practises the method four to five times a week. He says, “As an entrepreneur, I have to be aggressive in my way of life. I have noticed I have more control, mental focus and drive after my regular ice baths than when I don’t have one.”
Neurological benefits of an ice bath
When we dip ourselves in a shower with icy water, our parasympathetic nervous system kicks in instantaneously. A study published in Aviation, Space and Environment Medicine found that cold affects the vagus nerve, a nerve bundle connecting our gut, lungs, heart and brain. The vagus nerve is the crucial highway by which the parasympathetic system operates. This creates a wave of relaxation and de-stressing signals across the body.
“It decreases cortisol levels and the sympathetic nervous system activity,” says Dr Malasa Gujjar, a consultant psychiatrist at the Jindal Naturecure Institute, Bengaluru. After a method she often employs for her clients, she says the sudden cold stimulates a person to become alert and instinctively take deep breaths. This improves oxygenation of the body and consequently, the person’s concentration.
Studies show that repeated cold exposure decreases adrenaline and noradrenaline production, wherein the persons adapt themselves to the stressful temperature shock and improved parasympathetic activity. Conducted over a decade ago, this research tells us that it is not a new concept but could provide a simple idea of how to de-stress.
The dopamine release from a brief exposure to icy cold water boosts morale. It gives a well-needed pick-me-up for the day, according to a Czech study published in the European Journal of Applied Physiology.
Similarly, in an experiment, Dr Ala Yankouskaya and her team from Bournemouth University, England, scanned the brains of 33 healthy volunteers immediately after they bathed in cold water. The fMRI scans showed that neural connections in the medial prefrontal and parietal cortex had restructured in response to the cold shock. These were regions of the brain that control emotion, attention and decision-making. This explained why the participants felt alert and excited after the cold bath.
Resilience, grit and other benefits
In the past few years, many have taken up the ice bath challenge to regulate the nervous system, improve mental grit and resistance and to de-stress themselves physically and mentally. British soccer star David Beckham and US actor-singer Lady Gaga have adopted this routine for their psychological and physical health.
Scientists explored how this method can help people build resilience, reduce anxiety and feel better if they have been sad. Neuroscience podcaster Andrew Huberman has pointed out that deliberate exposure to cold builds resilience and grit in addition to giving one a dopamine boost. This resilience seeps into other daily activities.
Cricketer Mathias, who has created one of the first portable ice baths for regular use, says he frequently receives positive feedback from customers improved muscle endurance and focus.
Dr Gujjar of Jindal Naturecure notes that cold water immersion therapy sometimes works better at reducing anxiety than a 45-minute psychotherapy session to reduce anxiety. However, she cautions that it is not a replacement for medication or cognitive behavioural therapy.
“Bodily symptoms like anxiety, tremors, body heat and nervousness come down after a short cold water immersion therapy session,” she says. She suggests that people in warmer regions could try cold water baths over a week.
Physiological changes from cold water immersion
The effects of cold water immersion go beyond mood, focus and stress relief. The sudden cold-derived shock also acts as a brief trigger to activate the immune system, keeping it awake and active.
Dr Atraeyee Niharchandra, a psychologist, paediatrician and nutritionist based in Bengaluru, says she has observed that short sessions of cold water immersion regulate lymph node drainage and thus improve immunity.
She also recommends a simple face dip in a bowl of icy water for the same effects. (An added advantage is skin health!)
In ‘Health effects of voluntary exposure to cold water’ published in the International Journal of Circumpolar Health, the researchers observed a healthy fat loss on exposure to cold water.
David Mathias says, “I observed that my [body] fat decreased in a week even without any change in diet or exercise. By the end of the month, I had lost 4 kilos.” However, he clarifies that this depends on a person’s metabolism and may vary from person to person.
Precautions to follow
While cold water therapy has benefited many people, experts say it should not be tried without professional help. They advise people to keep these factors in mind:
- One should not to stay in cold water for very long as it can lead to hypothermia.
- Immediate care should be taken after stepping out of an ice bath.
The temperature of the water and the duration of immersion should be kept based on one’s individual metabolism.