The Transformative Power of Contrast Bathing

Enjoying a cool down in between sauna rounds with ice bathing and icy headstands

Going to the sauna is exciting, the thermal extremes waiting for us there give a powerful health boost for the whole body. Whilst the process is indeed relaxing for the mind, the body is about to be put through its paces, to do some work, and we have the opportunity to really explore where our edges are, to find our limits, and dance on them. This is the beauty of contrast bathing. Let’s dive right in!

Over in ‘Sauna, why it's more than just heat’ we already started to dissect a little on what sauna is and what it is not. It is not just about getting hot. It is about exposing the body to the opposing extremes of heat and cold with short breaks in between. As mentioned this is often referred to as hot and cold therapy, the nordic cycle, or most modernly Contrast Bathing and today's post is all about exploring what exactly this means, how best to do it and the most important bit, why do this? Why is it so good for us?

As mentioned in hot-cold-rest-repeat - we want to approach our sauna process in terms of rounds. How many times can we flow through this hot-cold-rest cycle? In a quick half hour sauna sesh we might aim for two good rounds, if the session is 60 mins then four rounds is achievable, 90mins perhaps a couple more. Interestingly the more the body acclimatises to the process, the number of rounds may be fewer but the length of each round, the more time spent in the heat and the cold, will be longer. Quality over quantity springs to mind. So then what makes a good round?

It’s always a good idea to start the sessions with a quick rinse, be this a shower, a bucket of cold water, a quick dunk in the cold-tub, when we enter the sauna with wet skin we conduct heat more efficiently and thus begin to heat more effectively. And this is where it begins, with the Hot! As we sit in the heat, adding scoops of water to the rocks, creating the steam, the löyly, that wraps itself around us completely, the body starts to warm up. The heart rate increases as the heart works harder to send blood to the surface of the skin, where excess heat can be released via the sweat. There is a vasodilation response, the body opens up, veins and capillaries widen to increase blood flow, pores open, sweat glands open producing beads of sweat designed to cool the skin. Increased blood flow to the brain stimulates production of norepinephrine which boosts focus and attention, feeling more present and in the now, and beta-endorphins also bring on a sense of calm, relaxation and feeling at ease. The body, the heart, the mind, everything ‘opens up’ in the heat. Increased blood flow to muscles also allows for the collection of metabolic waste, making sauna after exercise particularly good at combatting DOMS. The body may be sitting relatively still but there is a heck of a lot of activity going on particularly with internal systems - think heart, lungs, immune system, nervous system, everything is working hard to combat the extreme heat. There will be a point where the body begins to release dynorphin, an opioid produced in times of unease, signalling it’s time to get out of the heat, all part of the body’s thermo-regulation response. The heating process varies from person to person, but generally 15-20 minutes is a good guide. Of course this maybe shorter for newbies or those who sauna less frequently. 

Next up, the Cold, herein comes the contrast! Ideally you are able to step out of the hot-room and slip into the cold plunge! Please note, it's always better for the body to step into the cold, feet first, never diving head first as we can never be certain that this won't be too much of a shock for the brain and the body! However this does not mean dilly-dally! It is far better to step into the cold, and quickly but smoothly lower the whole body into the water, preferably right up to the neck, which most effectively stimulates the vagus nerve and brainstem. Standing shin-deep in baltic temperatures, umming and ahhing about going deeper, down to the thighs and then more oohing and ahhing, making a meal of it, this is not the way. Far better to just take a nice long exhalation, maybe even with an ahhhhhhh sound and just slide right in. Splash water on the face, tip the head back to immerse the head and scalp, all the better to kick start the cooling process, increasing vagal nerve activity and switching on the parasympathetic nervous system, the rest-and-digest response. Breath control is important here too. When we immerse in cold water we exhibit a cold-shock response, this brings on the gasp reflex, we literally suck in air and hold our breath (which is actually an indication of this opposing nervous system - fight, flight or freeze) so we must focus on the out-breath, the exhale, making this as slow and long as possible. The inhale will happen naturally, it’s all about the exhale. My favourite breath cue is ‘breath like you’re blowing out the candles on a birthday cake’ - this too will stimulate the vagus nerve, even more so if there is an ahhhhh sound, a sighing sound, more fodder for the parasympathetic system, moving into the relaxation response. Who would have thought it, submerging in freezing cold water is relaxing for the mind! Of course lots of activity is happening in the body too, mirroring a lot of what is happening during the heating process. All that warm, rich oxygenated blood that flooded the muscle and rose to the surface of the skin, now also carrying metabolic waste that has been collected, this is now pulled back to the core, filtering through liver and kidneys, being thus irrigated of waste. Veins and capillaries narrow, the opposite effect to vasodilation being vasoconstriction, , taking blood away from the surface in a bid to conserve heat. This process in itself, the widening and narrowing, the opening and closing, be it of vessels, of glands, of pours, is incredibly healthy for structural health. It is also thought to be particularly healthy for the vascular system, including changes in blood pressure which can also clear arterial build-up inside the blood vessels. Cold exposure also prompts receptors on the skin to send the message to the brain to produce those all in important neurochemicals - dopamine, serotonin, cortisol, norepinephrine, betaendorphins - again it’s a powerful cocktail of hormones which lead to increased mood, feelings of calm and relaxation, of alertness and focus, and have been proven to significantly reduce symptoms of anxiety, depression, cPTSD, insomnia and other mood-disorders. By now we can see just how powerful this cold component of our sauna practice is. 

The final and equally important step before hopping back into the heat is the rest, the time for the body to go through a short period of homeostasis, returning the body to a balanced state, reestablishing the equilibrium of the body. It is akin to the savasana at the end of your yoga practice, it is the time where the body become completely still to integrate the process that has just occurred. It is a time where the mind may be still, with space between the thoughts, a perfect time for a moment or so or meditation, of deep relaxation of the mind, nothing else matter here, the world and her problems are a million miles away. This, my friends, is the magic place! Hopefully here you can kick back into a deckchair, or perhaps lie down on the earth, grounding yourself and your energy. It’s the bliss state, anadamaya, perhaps here the body doesn't even exist anymore, all that you are now is a thinking thing (Hello Descartes). It’s arguably just as important as the heating and cooling components. Only a fool would skip the rest in between rounds! If it’s a really good sauna establishment, you might even get to lie down on a bed of hay, covered with a sheet, with the sound of birdsong floating through a speaker. The Rest is a really key component of the sauna!

And when you float back down to Earth after resting, drink some water, and it’s time to begin the process again. Another round. Another cycle through Hot-Cold-Rest. This time you will no doubt stay longer in the heat, you might be able to take more löyly, more steam, to go even hotter! Stepping into the cold may feel easier, quickly more blissful, you may stay longer in the cold, this is the beauty of the sauna process, it extends and expands around you the more you embark on the journey! You may find it more easy to switch off the thoughts and enjoy the bliss state, the meditative mindset between rounds. And then go again. And again. As much as time allows. 

But when is too much? When is enough enough? As you lean into the bodily processes that guide you through the session, you will naturally begin to feel when you are nearing the end of the session. It's common to hear the phrase ‘saunaed out’ - when sauna-goers feel they have done the work for the day. It’s just a natural feeling that occurs. Perhaps after the third or fourth round, a thought of ‘just one more round’ arises. This round may be naturally a little shorter, as we have now passed the peak of the session and are coming back down the other side. The final round may be a little shorter, and the final cold dunk a little briefer. Here we take it easy. Making sure we also have plenty time for a good rest at the end. 

It’s common as a sauna operator to see people wanting to end their session on Hot. To go home with all that lovely heat in the body. But we really should advise against this. To leave after the ot, is essentially leaving in a state of stress. We have activated the hormetic stress response in the body and left it hanging there, which is not necessarily good practice. Leaving on Hot can make sauna bathers feel tired, headachy, groggy and could also lead to a poor night’s sleep amongst other things. We must follow the Hot with the Cold, in order to activate the relaxation response; we also want to draw the warm blood back towards the core and allow the internal systems to continue working to cool the body. We want to end with that cocktail of feel-good hormones that the cold brings on. We want to allow the body time to rest and digest. 

This is also a reason why the rest zone is a vital part of any sauna set up, a place where sauna bathers can relax after the hot-cold cycle. If guests can change, dress and then sit for ten mins relaxing, they will no doubt leave feeling absolutely renewed and re-energised, and likely raring to return! The last thing any sauna operators want is for guests to leave and then experience negative effects after the session perhaps making them reluctant to return. 

For tips on what makes a good sauna set-up check out the dedicated post here.