Personal Fitness: Types of Muscles

Skeletal (Striated) muscles

Move your bones. You can see and feel them. They attach to the bones through tendons. They come in pairs- one muscle moves the bone in one direction and another moves it back. They are voluntary. Made up of long cylindrical fibers.

Smooth muscles

Found in the internal organs, blood vessels, and airways. Have the ability to stretch and maintain tension for long periods of time. They are involuntary.

Cardiac muscle

Found only in your heart. Also an involuntary muscle.

Isometric Contractions

Occur when there is a contraction of the muscle, but there is no movement. The muscle does not change its length. Ex: pushing or pulling an immoveable object.

Eccentric Contraction (Lengthening)

When the resistance used is more than the force produced by the muscle. The muscle is producing force, but it is "giving in" to the resistance.

Concentric Contraction (Shortening)

When your muscle produces more force than the resistance that opposes the movement. The result is that the muscle or muscle group becomes shorter.