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What makes muscles grow? - Jeffrey Siegel
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Muscles.
We have over 600 of them.
They make up between 1/3 and 1/2 of our body weight,
and along with connective tissue,
they bind us together, hold us up, and help us move.
And whether or not body building is your hobby,
muscles need your constant attention
because the way you treat them on a daily basis
determines whether they will wither or grow.
Say you're standing in front of a door, ready to pull it open.
Your brain and muscles are perfectly poised to help you achieve this goal.
First, your brain sends a signal to motor neurons inside your arm.
When they receive this message, they fire,
causing muscles to contract and relax,
which pull on the bones in your arm and generate the needed movement.
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