Why Is Being Underwater So Peaceful?


[intro] Summer is winding down here in the Northern
Hemisphere, which means we’ve started to reflect on
our long days at the lake and all the times we’ve jumped into swimming pools. And there’s one thing we’ve noticed: Being immersed in water is really relaxing. As it turns out, though, this isn’t just because of the warm weather
or the sound of the waves. There’s something larger at play here, called
the mammalian dive reflex. And you can actually take advantage of it
all year round, no pool required. When you dunk yourself in water, this reflex kicks in, and your body does some pretty interesting
things. Mainly, as soon as your face makes contact
with the water, it triggers a reduction in your heart rate
— called bradycardia. The effect happens very quickly, and studies have shown that the mammalian
dive reflex can drop someone’s heart rate by ten to 25%! This is what results in that nice, peaceful
feeling. Multiple studies have shown that when your
heart rate slows down, you feel calmer. This is also why breathing exercises are so
relaxing — although in that case, you’re slowing your heart rate through careful,
slow breaths. But while it’s a nice bonus, this reflex
doesn’t exist to help you chill out. Instead, research suggests it’s an evolutionary
adaptation that allows us to stay underwater for an extended
period of time. After all, lowering your heart rate ultimately
reduces the amount of oxygen entering your bloodstream, and it means your body can immediately start
conserving oxygen. Which makes sense because, you know, we kind
of stop breathing when we’re underwater. Additionally, the mammalian dive reflex causes
your body to divert blood from your extremities. Instead of getting pumped out to your fingers
and toes, the blood is redirected into your lungs and
other vital organs. This helps preserve your body’s temperature
in cold water, and might even help protect you from the powerful
crush of water pressure at deep depths. This reflex exists in all kinds of mammals,
from aquatic ones to terrestrial ones — including rodents and primates. Even newborn babies exhibit it! And what’s really interesting about this
reflex is that it’s triggered even when just your
face comes in contact with water! A big splash to the face activates receptors
in your nose and sinus cavity, and that triggers a physiological override
via your trigeminal nerve, which is the largest cranial nerve. This sends an immediate “hey-we’re-underwater-water-now”
message to the brain, and these physiological changes start to kick
in. So next time you feel stressed out, splash some water over your face, or go for
a dip! You can thank the mammalian dive reflex for
the chill vibes that come along with a nice soak. If you want to learn more about underwater
science, you can check out our episode about whether
humans could ever breathe underwater. And as always, thanks for watching this episode
of SciShow! [ outro ]

100 thoughts on “Why Is Being Underwater So Peaceful?”

  1. in islam, if you get angry, you are advised to take wudhu (ablution ritual before praying)
    and now, I know the scientific explanation behind it

  2. Uh I just like being able to move in three dimensions, it feels like I'm flying. Is it possible that you guy's are over thinking this a little.

  3. Hey SciShow, if an individual person can be identified via their DNA, could an individual dog be identified by their DNA? What about an individual bird, lizard, mollusk, plankton, tree, etc?

  4. I have the opposite effect. I hate water hitting my face, it stresses me out, so does being emerged in water. Maybe I enjoy a normal heart beat.

  5. I have an irrationally strong fear of drowning that probably verges on a phobia, so not only does submerging my face in water make me short of breath, but even watching this video brought my heart rate up lol o_O
    On the rare occasion I am persuaded to go swimming, there is indeed the tug-of-war between the calmness of feeling like my lungs are working really efficiently, versus my brain continually reminding me I could drown at any moment.

  6. Hello everyone, I think I might have discovered a very fascinating life-hack about this very topic some days ago, and it’s surprising to learn out of the blue that it has a scientific explanation!! Please, let me explain: Some months ago I had a very hard work schedule and spent hours and hours next to a van driver with a very curious trick he had in order to stay awake and freshen up given the extreme heat of Mexico City plus the never ending schedules (TV production): he carried around a plain, simple and cheap spray bottle of pure water, and he literally just sprayed his face with it every time he felt like sleeping or just thirsty. I started trying it some days ago after reading about this “5 Second Rule”, which goes around something like this: at the very time you realize you’re about to make a decision, counting 5 seconds will “reset” your mindset. Well, I find spraying water at your face just extremely effective and I literally can’t stop amazing myself every time I do it lmfao it may sound as the stupidest thing in the world, but it really brings your butt down to earth in a second, a very Zen experience if you will, and this video may be a very accurate explanation to this life-hack I think I discovered…. Just carrying around a simple spray bottle of water to spray your face and reset your mindset! Please ask me anything!

  7. True story, submerging your face in water can pretty much immediately stop a panic attack. I know from experience.

  8. I've been doing this ever since I was 12 years old. I fill a bucket with water and Walah.. I put my head in it and it helps me think better and relax my mind.

  9. Peaceful? Maybe in a shower or bath, but otherwise it's a high stress environment.

    Maybe this explains why I can't hold my breath underwater for very long. My heart rate probably elevates.

  10. I can tell you firsthand that I never feel so relaxed or centered as when I'm scuba diving. I'm more mindful of my breathing (gotta extend that bottom time!) and it's the closest I'll ever get to exploring an alien world. Moving in three dimensions is pretty damned cool as well. And yes, divers pee in their wetsuit to keep warm…or maybe that's just me. 😉

  11. I wonder if this helps make showers so relaxing and refreshing. whenever I take a shower, I feel like I could take on the world!

  12. Nonsense!
    People’s heart rate will fall if they just go to a quiet place and meditate.

    Tell people how much PEE or Chlorine is in that pool, and they won’t be so calm…

    .. or throw a shark in there and see how calm people get…

  13. >"thanks to a reflex we share with all air-breathing vertebrates"
    >Still call it "Mammalian dive reflex"

    Come on, you people

  14. Blurred vision unable to make out dangerous animals, inability to breath, slow moving in comparison to the underwater world. It’s not peaceful, it’s a freezing moment of fright.

  15. In hospital we use the mammalian dive reflex to treat some heart arrhythmias. Dunking a patient in a basin full of ice water works a treat to "break" SVT and rapid atrial fibrillation, especially if the patient isn't responsive to medication.

  16. It's not. You can't breath and pressure is equally hard to ignore. going to the woods in the middle of January in Minnesota is peaceful.

  17. So what about people that can't stand being in the water? Not hydrophobia, but people that don't like the feel of water or wet clothes.

  18. Relaxing? I'm afraid of diving in water because it's deep and I especially dont like seeing how deep I am in the water…. Seeing the water get darker and darker as the bottom gets farther and farther away….

  19. I hate the dry, gutteral endings on her words. Stop with the Californian psuedo-hipster presenters with Jill Abramson accents.

  20. I suffer from anxiety and insomnia and this is exactly what my therapist told me to do- get my face wet and hold my breath for a bit. It's really trippy how noticeable the effect is.

  21. Very cool. I would've assumed it had something to do with being formed in a fluid sac in the womb and having a carry over sensation as we get older

  22. I can't watch it, I tried. Her voice is like fingernails on chalkboard. I hate how she drops an octave and trails off with EVERY SENTENCE. It makes me cringe. Sucks because I really want to watch it.

  23. In the scientific research industry, it is rather difficult to see people with tattoos or ridiculous accessories.

  24. Why do you call it mammalian when even fish have it just in reverse? When their face is out of water they show the same symptoms.

  25. I never considered that this could be a thing. I can hold my breath about a minute above water, but diving to 12 ft causes me to panic and I just can't hold it longer than maybe 20 seconds.

  26. As the reflex is related only with mammals, this makes me think from a development standpoint that being underwater recreates being in the womb.

  27. In Islam ,before you pray you must Splash water all aroud your face and then you will feel calmer and the Secret IS mamalian dive reflex !!

  28. Funny cause I always have nightmares about being in a large sea
    And just watching the beach terrifies me😑

  29. Any reason why being in water would make you just really sad and depressed? As soon as I dive in, I feel the need to cry, which makes the water really convenient.

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