Eccentric contraction occurs when the total length of the muscle increases as tension is produced. For example, the lowering phase of a biceps curl constitutes an eccentric contraction. Muscles are capable of generating greater forces under eccentric conditions than under either isometric or concentric contractions.

What are examples of eccentric contraction?

Movements that employ eccentric contractions include walking down stairs, running downhill, lowering weights, and the downward motion of squats, push-ups or pull-ups.

In which phase target muscles are contracting eccentrically?

An eccentric contraction refers to any contraction where the muscle lengthens under load or tension. So in the squat exercise, the quadriceps muscles will contract eccentrically (lengthen) in the downward phase of the movement (the opposite direction of the arrow), as can be seen in the adjacent picture.