When your body has adapted to an activity, it won't produce enough stress to stimulate new muscle growth.  <ul><li>Hypertrophy, an increase in muscular size through exercise, is possible by exposing your cells to higher workloads than they are used to. </li><li>If you don't continuously expose your muscles to some resistance, they will shrink, known as muscular atrophy.</li><li>Exposing the muscle to a high degree of tension while the muscle is lengthening is called an eccentric contraction.</li></ul>

Hypertrophy, muscular atrophy and eccentric contraction

When you expose your body to stress, such as pushing something heavy, your muscles experience microscopic damage. In response, the injured cells release inflammatory molecules called cytokines that activate the immune system to repair the injury. This is when muscle-building happens. The greater the damage to the muscle tissue, the more your body needs to repair itself. The cycle of damage and repair makes muscles bigger and stronger to adapt to greater demands.

Muscles stress

We have over 600 muscles that make up between 1/3 and 1/2 of our body weight. They bind us together along with connective tissue and help us move.  Muscles need constant attention. The way you treat them on a daily basis will determine if they will wither or grow.

Muscles need attention to grow

Without proper nutrition, hormones, and rest, your body will not be able to repair damaged muscle fibres.<ul><li>Protein in our diet preserves muscle mass. It provides the building blocks for new tissue in the form of amino acids.</li><li>Hormones such as insulin-like growth factors and testosterone shift the body into repair and growth.</li><li>However, this repair mainly happens when we're sleeping.</li></ul>

Muscles need proper nutrition and sleep

podcasts

Podcasts

videos

Videos

sports

Sports

health

Health

exerciseandfitness

Exercise & Fitness

How To Build Muscle

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.

scienceandnature

Science & Nature

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.

TED-Ed’s mission is to create lessons worth sharing. Feed and expand your curiosity with our award-winning animated shorts - published on YouTube and available with supplemental learning materials on ed.ted.com.

Want to suggest an idea for a TED-Ed animation, nominate an educator or animator? Visit our website at: http://ed.ted.com/get_involved.

Consider backing us on Patreon. By doing so, you directly support our nonprofit mission to create free, high-quality educational content: https://www.patreon.com/teded

For more information on using TED-Ed content for commercial purposes (e.g. employee learning, in a film, or in an online course), please submit a Media Request using this link: https://media-requests.ted.com/ 
