[0:00] We all have a fascination with muscles and
strength - whether we want to be stronger,
[0:04] feel better, or look like superman; and there
are many proposed strategies and exercise
[0:08] regimens to get this done.
[0:10] But what if I told you that it was out of
your control, and that your genetics may be
[0:14] entirely holding you back?
[0:16] Conversely, what if there was a secret out
there that could lead you to super human strength?
[0:21] The truth is: your muscle size has a limit.
[0:24] Sure, it may seem obvious when you hear it,
but your muscles are under the strict control
[0:28] of a protein called Myostatin, which determines
exactly how large a muscle can become.
[0:33] And this limit is different for everyone depending
on their myostatin levels.
[0:37] As a muscle reaches this limit, myostatin
prevents any further growth.
[0:40] But if the myostatin itself is limited or
absent, this muscle limit suddenly goes away.
[0:46] This phenomenon was first noticed in Belgian
Blue Cattle.
[0:49] These cows developed 2-3 times more muscle
mass than a normal cow, and it was later discovered
[0:54] that they had a deletion of the gene GDF-8,
which just so happens to create myostatin.
[1:00] As a result, without any exercise or special
diet, these cows have incredible muscle mass.
[1:05] Similar cases have been documented in dogs,
mice, and even a few cases of human babies
[1:10] lacking the GDF-8 gene.
[1:13] These findings have helped scientists understand
why some people bulk up easily, while others
[1:17] struggle to.
[1:18] Lower levels of myostatin = more muscle mass.
[1:21] In fact, some studies have even shown that
many champion body builders have naturally
[1:25] lower levels, or even entire deletions of
the myostatin gene.
[1:29] If you look at somebody like Arnold Schwarzenegger,
as a teen, he just looks naturally muscular.
[1:34] As such, perhaps many champion bodybuilders
owe their success more to genetics than their
[1:39] training or drug use.
[1:41] Eventually, it may be possible to develop
drugs which deplete or block myostatin.
[1:45] Of course, it's a double edged sword; On the
one hand, patients with muscular dystrophy,
[1:50] or muscle loss from aging could regrow and
restore muscle.
[1:53] On the other hand, the potential for abuse
as performance enhancers seems...inevitable.
[1:58] But, the prospect of seeing a real-life human
Hulk...seems kind of cool.
[2:03] Besides, should those who already have low
levels of myostatin be considered to have
[2:07] an unfair advantage?
[2:09] It's hard to say.
[2:10] Regardless, be weary of anybody selling or
promoting this unproven and unregulated treatment.
[2:15] At the end of the day, whether you have naturally
low or high myostatin levels, remember - this
[2:20] is the level that is optimal for your mechanical
and metabolic efficiency.
[2:24] With proper exercise and general health, you'll
reach your own unique physiological peak.
[2:29] And while you may not be destined to pack
a punch like Superman, you can push your own
[2:33] limits through training and hard work.
[2:35] But, what if you could punch as hard as Superman?
[2:38] Our friend Jake over at Vsauce3 has the answer
to this smashing superhero question, which
[2:43] you definitely need to check out.
[2:45] And if you want to know how much myostatin
you have...there's only one real way to find
[2:49] out.
[2:50] Get working.
[2:52] This episode of AsapSCIENCE is supported by
23 and Me.
[2:55] 23 and Me is a DNA analysis service that allows
you to explore your own genes.
[2:59] Whether you are interested in discovering
your global origins, or understanding your
[3:02] health and your risk for disease, be sure
to check out 23andme.com/asap.
[3:07] With the help of their DNA kits, connect to
your past, learn about your present health
[3:10] and potentially be part of future genetic
research, all at 23andme.com/asap.
[3:16] And subscribe for more weekly science videos.