I grew up in a coastal town in Victoria, Australia, where I remember the beaches being windy and cold. When I was a kid, my father, a surfer, took it upon himself to ensure I knew my way around the Ocean. On the weekends, when I wanted to hang out with my friends, play music and pretend I was in No Doubt, my dad would insist on taking me surfing. He’d call me at my mum’s house in the morning and ask if I wanted to “look at the surf” with him and I’d usually reluctantly agree to go. We’d get to the beach and look out into the Ocean at the waves. It occasionally looked clear and inviting, but usually looked choppy and intimidating. As cold wind pierced my ears, I would dream of going home and my dad would say “looks surfable”, which meant I had to go out. I’d step into my cold wetsuit, zip it up, grab my board and slowly walk to water. I’d paddle in, trying not to get thrown off my board as I made my way to the break out- the-back. Because I’d never learned to duck dive, I’d often get thrashed around by waves on the way out. Often when I saw a big wave coming, I would quickly swing around to catch it, fearing it would crash over me if I didn’t. Once I felt my board moving down the wave, I’d jump to my feet and start riding. Or I would fall off. My body would be pushed under the wave, and tumble around in the rolling water. I found that if I resisted, the experience would be worse, my limbs pulled in several directions and my leg rope winding around my leg. When I allowed myself to let go, and moved with the Ocean, it felt better, I was more relaxed. Finally, I’d come up to the surface, gasp for air, and it was time to paddle out again. If a big wave came, I’d pivot around and start over.
I have always felt ambivalent about surfing, given that my participation in it was not always voluntary. This being the case, I’m overall grateful for being “encouraged” to surf and to become familiar with the Ocean. For one, the times when I have caught long clean waves into the beach have been fun and allowed me to know what it means to be “stoked”. Also, there is something to be said for wipe-outs. Learning to roll with the ocean as it wallops me around has been character building. It has taught me lessons about being present, letting go and humility. And the physical feeling after a surf is very satisfying- tired, calm and hungry. My curiosity about the therapeutic benefits of water has led me to learn of a phenomenon referred to as the “mammalian dive reflex”. This describes the rapid physiologic changes that occur when a mammal’s face is submerged in cold water(1). This reflex has been shown to be present across several species of mammals including seals, dolphins, whales, rats, mice and humans and is thought to serve as a mechanism to prevent asphyxiation(2). The mammalian dive reflex consists of apnea, bradycardia and increased peripheral resistance, which serve to conserve oxygen stores during underwater submersion(1). The reflex appears to be stimulated when the nasal mucosa is exposed to water, which in turn sends sensory information to the brainstem via the trigeminal nerve(2). The brainstem then stimulates bradycardia via the vagus nerve of the parasympathetic nervous system(2). Additionally, carotid bodies in the aorta sense a drop of oxygen in the lungs, which stimulates the sympathetic nervous system to promote peripheral vasoconstriction, shunting oxygen to vital organs including the heart and brain(1). The mammalian dive reflex has been harnessed by medicine as a treatment for paroxysmal supraventricular tachycardia (PSVT), given its rapid ability to induce bradycardia via increasing vagal tone(3). Because of its ability to promote the parasympathetic nervous system, it is hypothesized that the mammalian dive reflex may be useful in the treatment of anxiety(2). Additionally, the reflex has been shown to increase cerebral blood flow, suggesting that it may have a place in the prevention of migraine headaches and mitigating the negative effects of stroke(2).
In my experience, being underwater has been therapeutic because it has forced me to exist in the present moment. When pushed under a wave, my choices are limited, I must simply be in the experience. There a series of distress tolerance techniques taught in dialectical behavioral therapy (DBT) known as the “TIPP”, which stands for temperature, intense exercise, paced breathing and progressive muscle relaxation(4). These techniques can induce rapid physiologic changes that in turn mediate psychological distress. For the temperature piece, it is often suggested to splash the face with cold water, which would likely induce the mammalian dive reflex and increase parasympathetic tone. Another method is to dunk oneself in the Ocean. As humans, we seem to know inherently that there is something soothing about spending time in the water. Despite the Ocean often seeming cold, brutal and intimidating, many of us choose to spend time in the sea water and come out feeling refreshed. It seems we have evolved with the mammalian dive reflex in order to stay close to the Ocean and other bodies of water. Emerging research suggests that surfing can promote a sense of wellbeing among people suffering from mental health disorders including PTSD(5)(6). The physical activity, social interaction and respite experienced at the beach are thought to contribute to its therapeutic benefit(6). It appears to me that the mammalian dive reflex also plays a role because it induces an embodied sense of calm under challenging circumstances.
References
Godek D, Freeman AM. Physiology, Diving Reflex. In: StatPearls. StatPearls Publishing; 2021. Accessed August 26, 2021. http://www.ncbi.nlm.nih.gov/books/NBK538245/
Panneton WM, Gan Q. The Mammalian Diving Response: Inroads to Its Neural Control. Front Neurosci. 2020;14:524. doi:10.3389/fnins.2020.00524
Smith G, Morgans A, Taylor DM, Cameron P. Use of the human dive reflex for the management of supraventricular tachycardia: a review of the literature. Emerg Med J. 2012;29(8):611-616. doi:10.1136/emermed-2011-200877
DBT : TIPP - Skills, Worksheets, Videos, & Activities. DBT. Accessed September 1, 2020. https://dialecticalbehaviortherapy.com/distress-tolerance/tipp/
Godfrey C, Devine-Wright H, Taylor J. The positive impact of structured surfing courses on the wellbeing of vulnerable young people. Community Pract. 2015;88(1):26-29.
Caddick N, Smith B, Phoenix C. The effects of surfing and the natural environment on the well-being of combat veterans. Qual Health Res. 2015;25(1):76-86. doi:10.1177/1049732314549477