An eccentric contraction occurs when a muscle lengthens while under tension. This type of contraction happens during activities like lowering a weight or descending stairs, where the muscle must control the movement against gravity. Eccentric contractions are essential for activities that require stability and control. During an eccentric contraction, the muscle fibers generate force while elongating, which can lead to muscle soreness if performed excessively. This process is crucial for muscle development and strength, as it helps improve overall performance in sports and daily activities. Understanding eccentric contractions can aid in designing effective training programs.