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What is muscle?

Muscle refers to the tissue in the body that contracts and relaxes to create movement. There are three types of muscle:

  • Skeletal muscle: also known as striated muscle, it's attached to bones by tendons and is responsible for moving the body.
  • Smooth muscle: found in the walls of internal organs, it's responsible for involuntary movements like digestion and breathing.
  • Cardiac muscle: found only in the heart, it's responsible for pumping blood throughout the body.

How do muscles work?

Muscles work by contracting and relaxing in response to electrical signals from the brain. When a signal is sent to a muscle, it causes the fibers to contract, which shortens the muscle and creates movement. When the signal is stopped, the fibers relax and the muscle returns to its resting state.

How can muscles be trained?

Muscles can be trained through exercise, specifically resistance training or weightlifting. This involves lifting weights or using resistance bands to place stress on the muscles, which in turn causes the fibers to break down and rebuild stronger. Cardiovascular exercise like running or cycling can also help to strengthen and tone muscles, particularly in the legs and glutes.

Synonyms and Antonyms

Synonyms for muscle include tissue, fiber, and sinew. Antonyms include fat and adipose tissue.

Related Terms

Related terms include strength training, resistance training, weightlifting, hypertrophy, and atrophy.

Madeleine Smith

Content Lead at

Madeleine is passionate about empowering individuals with the information and tools they need to transform their bodies and lives.