During a resistance training session, which type of contraction occurs when the muscle lengthens?

The type of contraction that occurs when the muscle lengthens is called an eccentric contraction. During this process, the muscle generates force while simultaneously elongating. This often occurs when a muscle is under tension while being stretched, such as during the lowering phase of a bicep curl when the arm is extended. Eccentric contractions are crucial in activities where the control of movement is needed, such as lowering the body during a squat or the descent in a push-up.

This type of contraction is particularly important for muscle growth and strength development, as it can produce greater force than concentric contractions (where the muscle shortens). Eccentric contractions also play a significant role in activities that prevent injuries, as they help in controlling the load and impact placed on the muscles and joints.

Other forms of contractions mentioned, such as isometric and concentric contractions, describe different muscle actions. Isometric contractions occur when the muscle generates force without changing length, maintaining a static position. Concentric contractions, on the other hand, involve the muscle shortening while producing force. Static contraction is another term that can refer to isometric contractions, where the muscle remains engaged but does not change length.