Which contraction occurs when a muscle lengthens under load?

• A. Concentric contraction
• B. Isometric contraction
• C. Eccentric contraction
• D. Plyometric contraction

Answer: (C)

When a muscle lengthens while under control and resisting a load, that’s an eccentric contraction. In this type, the muscle is generating tension while it lengthens, which happens when the external load is greater than the muscle’s force and you’re slowing or lowering a movement. This is why you feel the muscle work as it lengthens during movements like lowering a weight or descending stairs.

Concentric contraction is the opposite: the muscle shortens under load (lifting). Isometric contraction means the muscle tenses without changing length (holding a position). Plyometric refers to a training method that uses an eccentric action followed by a rapid concentric action to develop power, not a single contraction type by itself.