What kind of muscle contraction occurs during lowering a weight?

The process of lowering a weight involves an eccentric contraction. During this type of contraction, the muscle lengthens while it is under tension. When you lower a weight, such as during a bicep curl where the arm extends back down after lifting, the muscles are still actively resisting the force of gravity while controlling the descent.

Eccentric contractions are crucial for activities involving deceleration and controlled movements, allowing muscles to absorb energy and prevent injury. This is different from other types of contractions, such as concentric contractions where muscles shorten while generating force, and isometric contractions where muscles generate force without changing length. In the context of lowering a weight, the purposeful lengthening of the muscle under load is what defines the eccentric contraction.