What type of muscle contraction is referred to as 'concentric'?

Concentric muscle contraction refers to the process where a muscle generates force while shortening. This type of contraction occurs when the muscle fibers contract and draw closer together, effectively pulling the ends of the muscle closer, which results in movement of the associated skeletal structure. For instance, when lifting a weight during a bicep curl, the bicep muscle shortens as it generates the force needed to lift the weight up.

Understanding this concept is essential because it highlights how muscles function during various types of activities, especially in resistance training and physical fitness scenarios. It contrasts with other forms of muscle contractions, such as eccentric contraction, where the muscle lengthens under tension, and isometric contraction, where the muscle maintains its length despite the presence of tension.