Name: 筋肉は実際にどのようにして大きくなるのか？ (How Do Muscles Actually Get Bigger?)
Uploaded: 2021-01-14T05:34:44.000Z
Duration: 2 min 38 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

様態の副詞

Hey guys, Amy here on DNews answering your questions about muscles! Neko recently asked

us if we can make a video about why our muscles grow big when we exercise.

We all want to get big and strong, building muscles to have lean bodies and to be able

to squat our coworkers for funsies. But what actually happens when you workout that makes

There’s more to muscles than you might think.

We have different types of muscles: cardiac, smooth, and skeletal muscles. Smooth muscles

are responsible for the contracting movements of hollow organs like blood vessels, the gastrointestinal

tract, bladder, and uterus. Skeletal muscles are made up of bundles of individual muscle

fibers that are themselves strands of proteins that grab onto one another and pull. These

muscle are attached to bones, and it’s the contraction, that pulling, that causes your

bones to move around your joints. That’s what happens when your muscles contract. These

are controlled by the somatic nervous system. The cardiac muscle, the one that makes your

heart pump blood throughout your body, is involuntarily controlled.

Your heart and the muscles that control it are obviously an important part of working

out or playing sports, but when we’re talking about building muscles we need to focus on

There’s a little more to skeletal muscles than just the fibers that make them up. Muscle

are broadly categorized into two types. Type I or slow twitch muscles are more efficient

at using oxygen to generate energy. And as the name suggests they can work longer before

being exhausted so these are the ones that you use for duration sports like long distance

running. Type II or fast twitch muscles rely on anaerobic metabolism to create fuel, or

more simply, they use your body’s stored energy for shorts bursts of activity. These

are the ones your body uses when sprinting or weightlifting.

When you build muscle, you’re actually breaking down these muscle fibres and building them

There are a couple of ways to do this. Hypertrophy is an increase in the size of the muscle due

to an increase in the size of the muscle fibers; while hyperplasia happens when you actually

split muscle fibers to eventually grow more of them, though some trainers suspect that

this splitting doesn’t actually create new fibers, it just changes existing ones.

The exact process of muscle growth isn’t entirely understood, but leading theories

say that lifting something heavy, like a weight, breaks the muscle fibers apart, and then those

fibers grow back in a way that allows them to compensate for the damage and protect themselves

against future damage. This happens naturally, but lifting speeds the cycle up so you rebuild

muscle faster, and the more you breakdown the more you grow back!

Which is why you need to rest between workouts; you need to give your body time to repair

itself, and help that process along with protein. And that’s where the increase to muscles

Speaking of bulking up,Toyota has been doing some augmentation of their own with the TRD

line of Toyota Trucks. Enhanced to rule the off-road!

So does this clear things up or do you still have more questions about muscles?

Let us know in the comments below or on Twitter @DNews. And of course, for more DNews every

single day of the week, don’t forget to subscribe!