大家好 我是大卫 这里是《分钟地球》
Hi, this is David from MinuteEarth.
When I try to hold my breath for as long as possible,
I can only last for about a minute
before I need to gasp for air.
That’s because humans need oxygen to survive,
so our bodies have several systems designed
to make sure we get new supplies of regular intervals,
but the best breath holders in the world had figured out how to hack three of the survival systems
and as a result, they can hold their breath for an astonishing amount of time.
嗨 抱歉中断了你的观看 但是
Hi, sorry to interrupt, but…
some of this next stuff is really really dangerous,
and you definitely shouldn’t try it at home.
Actually, don’t try it anywhere!
The first survival system that gets hacked is our fight or flight response.
Our brain understandably feels threatened when we start to use up our oxygen.
But this panic over running out
of air causes our heart to beat faster, which ironically
导致我们消耗 比一开始就不恐慌要消耗的 更多氧气
causes us to expend more oxygen than we would have if we hadn’t panicked in the first place.
However, the best breath holders can avoid this vicious cycle;
through intensive training,
they’re able to remain calm and
keep their heartbeat steady even as oxygen runs low,
allowing them to double their breath-holdingtime.
The second survival system they hack is themammalian dive reflex.
It turns out that all mammals – and thus all humans –
have developed an anti-drowning mechanism
for when they unexpectedly find themselvesunderwater.
When we get dunked,
a branch of one of our cranial nerves senses the temperature and pressure change
and alerts our brain to beginrationing oxygen.
Our brain tells our heart to slow waaaay down,
which slows down the rate at which we use oxygen.
Then the blood vessels on our skin and in our limbs constrict
directing more of the blood flow – which contains oxygen – towards our brain and other vital organs.
Finally, our spleen – which serves as a blood reservoir – contracts,
sending out a bunch
of backup oxygen-rich red blood cells intoour bloodstream.
Since this only happens when your face is underwater,
the best breath holders take advantage
of this adaptation by… well…
putting their heads in the water, which allows them to hold
their breath up to 50 % longer than they can on dry land.
The third survival system they hack is thediaphragm spasm.
When your oxygen level falls below a certain point,
it causes your diaphragm to start spasming,
which painfully jerks on your lungs,
basically yelling at them to get more oxygen as soon as possible.
But elite breath holders have figured out that
at that point there’s still some oxygen left.
So they repeatedly ignore those spasms,
which allows them to hold their breath for several more minutes.
In fact, some of them have trained themselves to let their oxygen levels fall to just before
it causes them to blackout – before they finally gasp for air.
The world’s best breath holder can withstand more
than 75 of these distress spasms, which,
helps him hold his breath for more than 11 minutes;
that’s long enough to watch this video 4 times in a row.
You probably shouldn’t try to hack your body,
and you definitely shouldn’t let someone else hack your identity.
That’s why I use Dashlane to keep me safeonline.
In addition to randomly generating a unique strong
password whenever I sign up for a new account,
it also lets me know
if there’s been a data breach at any of my regular haunts.
Dashlane also has a secure multi-country VPN for all my devices,
and security alerts if it finds my data on the dark web.
To download your own free 30-day trial of Dashlane Premium, go to Dashlane.com/MinuteEarth.
The first 200 viewers can also get 10 %
off a yearly Dashlane Premium membership using
the code MINUTEEARTH at checkout.
大家好 我是大卫 这里是《分钟地球》