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The surprising reason our muscles get tired - Christian Moro

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TEDEd Animation

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You're lifting weights. The first time feels easy, but each lift takes more and more effort until you can’t continue. Inside your arms, the muscles responsible for the lifting have become unable to contract. What’s going on? Christian Moro explains how exactly our muscles operate, and what causes them to become fatigued.

Skeletal muscles can only contract in one direction. As such, many of them are paired with muscles that contract in the opposite direction. These groups are called antagonistic pairs, with examples being the biceps and triceps, or the hamstrings and quadriceps. Can you describe any other muscles that work together as antagonistic pairs?

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TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Christian Moro
  • Director Nichola Latzgo
  • Narrator Addison Anderson
  • Animator Nichola Latzgo
  • Designer Nichola Latzgo
  • Producer Aaron Augenblick
  • Sound Designer Nichola Latzgo
  • Director of Production Gerta Xhelo
  • Editorial Producer Alex Rosenthal
  • Associate Producer Bethany Cutmore-Scott
  • Associate Editorial Producer Elizabeth Cox
  • Script Editor Eleanor Nelsen
  • Fact-Checker Laura Shriver

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