What makes muscles grow? - Jeffrey Siegel
-
0:07 - 0:08Muscles.
-
0:08 - 0:10We have over 600 of them.
-
0:10 - 0:14They make up between
1/3 and 1/2 of our body weight, -
0:14 - 0:16and along with connective tissue,
-
0:16 - 0:20they bind us together, hold us up,
and help us move. -
0:20 - 0:23And whether or not body building
is your hobby, -
0:23 - 0:25muscles need your constant attention
-
0:25 - 0:28because the way you treat
them on a daily basis -
0:28 - 0:31determines whether
they will wither or grow. -
0:31 - 0:34Say you're standing in front of a door,
ready to pull it open. -
0:34 - 0:39Your brain and muscles are perfectly
poised to help you achieve this goal. -
0:39 - 0:43First, your brain sends a signal
to motor neurons inside your arm. -
0:43 - 0:46When they receive this message,
they fire, -
0:46 - 0:49causing muscles to contract and relax,
-
0:49 - 0:53which pull on the bones in your arm
and generate the needed movement. -
0:53 - 0:57The bigger the challenge becomes,
the bigger the brain's signal grows, -
0:57 - 1:01and the more motor units it rallies
to help you achieve your task. -
1:01 - 1:05But what if the door
is made of solid iron? -
1:05 - 1:07At this point, your arm muscles alone
-
1:07 - 1:10won't be able to generate
enough tension to pull it open, -
1:10 - 1:14so your brain appeals
to other muscles for help. -
1:14 - 1:18You plant your feet, tighten your belly,
and tense your back, -
1:18 - 1:20generating enough force to yank it open.
-
1:20 - 1:25Your nervous system has just leveraged
the resources you already have, -
1:25 - 1:26other muscles,
-
1:26 - 1:28to meet the demand.
-
1:28 - 1:29While all this is happening,
-
1:29 - 1:33your muscle fibers undergo
another kind of cellular change. -
1:33 - 1:38As you expose them to stress,
they experience microscopic damage, -
1:38 - 1:40which, in this context, is a good thing.
-
1:40 - 1:46In response, the injured cells release
inflammatory molecules called cytokines -
1:46 - 1:50that activate the immune system
to repair the injury. -
1:50 - 1:54This is when the muscle-building
magic happens. -
1:54 - 1:56The greater the damage
to the muscle tissue, -
1:56 - 1:59the more your body
will need to repair itself. -
1:59 - 2:02The resulting cycle of damage and repair
-
2:02 - 2:05eventually makes muscles
bigger and stronger -
2:05 - 2:08as they adapt to progressively
greater demands. -
2:08 - 2:12Since our bodies have already adapted
to most everyday activities, -
2:12 - 2:15those generally don't produce
enough stress -
2:15 - 2:17to stimulate new muscle growth.
-
2:17 - 2:21So, to build new muscle,
a process called hypertrophy, -
2:21 - 2:25our cells need to be exposed to higher
workloads than they are used to. -
2:25 - 2:30In fact, if you don't continuously expose
your muscles to some resistance, -
2:30 - 2:31they will shrink,
-
2:31 - 2:34a process known as muscular atrophy.
-
2:34 - 2:38In contrast, exposing the muscle
to a high-degree of tension, -
2:38 - 2:40especially while
the muscle is lengthening, -
2:40 - 2:43also called an eccentric contraction,
-
2:43 - 2:47generates effective conditions
for new growth. -
2:47 - 2:50However, muscles rely on more than
just activity to grow. -
2:50 - 2:53Without proper nutrition,
hormones, and rest, -
2:53 - 2:57your body would never be able
to repair damaged muscle fibers. -
2:57 - 3:00Protein in our diet preserves muscle mass
-
3:00 - 3:02by providing the building
blocks for new tissue -
3:02 - 3:04in the form of amino acids.
-
3:04 - 3:08Adequate protein intake,
along with naturally occurring hormones, -
3:08 - 3:11like insulin-like growth factor
and testosterone, -
3:11 - 3:16help shift the body into a state
where tissue is repaired and grown. -
3:16 - 3:20This vital repair process mainly occurs
when we're resting, -
3:20 - 3:22especially at night while sleeping.
-
3:22 - 3:25Gender and age
affect this repair mechanism, -
3:25 - 3:28which is why young men
with more testosterone -
3:28 - 3:30have a leg up in the muscle building game.
-
3:30 - 3:35Genetic factors also play a role
in one's ability to grow muscle. -
3:35 - 3:38Some people have more robust
immune reactions to muscle damage, -
3:38 - 3:42and are better able to repair
and replace damaged muscle fibers, -
3:42 - 3:45increasing their
muscle-building potential. -
3:45 - 3:48The body responds to the demands
you place on it. -
3:48 - 3:52If you tear your muscles up,
eat right, rest and repeat, -
3:52 - 3:57you'll create the conditions to make your
muscles as big and strong as possible. -
3:57 - 4:00It is with muscles as it is with life:
-
4:00 - 4:03Meaningful growth requires challenge
and stress.
- Title:
- What makes muscles grow? - Jeffrey Siegel
- Speaker:
- Jeffrey Siegel
- Description:
-
View full lesson: https://ed.ted.com/lessons/what-makes-muscles-grow-jeffrey-siegel
We have over 600 muscles in our bodies that help bind us together, hold us up, and help us move. Your muscles also need your constant attention, because the way you treat them on a daily basis determines whether they will wither or grow. Jeffrey Siegel illustrates how a good mix of sleep, nutrition and exercise keep your muscles as big and strong as possible.
Lesson by Jeffrey Siegel, animation by Brett Underhill.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 04:20
Jessica Ruby approved English subtitles for What makes muscles grow? | ||
Jessica Ruby edited English subtitles for What makes muscles grow? | ||
Jessica Ruby accepted English subtitles for What makes muscles grow? | ||
Jessica Ruby edited English subtitles for What makes muscles grow? | ||
Jessica Ruby edited English subtitles for What makes muscles grow? | ||
Jennifer Cody edited English subtitles for What makes muscles grow? | ||
Jennifer Cody edited English subtitles for What makes muscles grow? |