Controlled cold exposure, particularly by immersing yourself in cold water such as in a cold shower, cold bath or getting in a cold body of water, has an instant and enduring effect on your mood. There is both a physiological as well as a psychological procedure that occurs throughout the body which upgrades your brain in the process. Well, what’s going on in there?

To explain, we need to familiarise ourselves with the excitatory neurotransmitter in the brain; Glutamate. Glutamate plays an important role in fundamental brain functions however, excessive levels of Glutamate in the brain – known as Glutamate excitotoxicity – is a problem because it creates a sort of physiological cascade that gets progressively worse. This is because high glutamate starts to kill brain cells and in return dying brain cells release even more glutamate and the pattern continues downwards. So what does cold have to do with it?

Well, getting cold halts this process and resets Glutamate, in return stopping that downward spiral of negative physiological effects. In fact, controlled cold exposure is regularly used in a medical capacity to treat many cases of brain cell death such as traumatic brain injury, spinal cord injury, lack of oxygen to the brain after a heart attack or stroke, neurodegenerative diseases etc. In all of these cases there will be a level of Glutamate excitotoxicity being experienced and you’ll see that in hospitals, the go to treatment to prevent further brain damage is to induce hypothermia.

If you have a newborn that has become hypoxic at birth, there’s probably going to be some brain damage but you don’t want it to get worse through Glutamate excitotoxicity. So they’re often put into induced coma, they’re put into induced hypothermia, they get a big cold ice blanket put around them. So this practice of controlled cold exposure is a common treatment.

Anyone can implement a version of this treatment in their day to day life. Take the time to get into some cold water, shock your system, reset your brain and get Glutamate back down to normal. What does good practice look like? Good is as simple as just turning the shower all the way to cold and standing under it. What does better practice look like? Fill the bath with cold water and lounge in there for a bit longer, somewhere between 5 and 10 minutes. What does best practice look like? Take this as a chance to get out into nature, into a cold body of water like a lake or the sea and submerge yourself neck deep for 10 minutes. Depending on where you live and the time of year, water temperature may not get cold enough for a good shock to the system. In that case, braving an ice bath (preferably shoulder/neck deep) once or twice a week will be the easiest way to routinely practice controlled cold exposure.

So what are you waiting for? Try cold water therapy and upgrade your brain.


Listen in as Prof Grant Schofield talks with Kathryn Ryan on Radio New Zealand about the growing body of research and his own experiences with the benefits of cold water: Dive in! The benefits of cold water swimming