International Sports Sciences Association (ISSA) Corrective Exercise Practice Test

During the eccentric phase of an exercise, the muscle lengthens while it is under tension. This occurs when the muscle is actively resisting a load while being elongated by an external force or load. For example, during a bicep curl, the eccentric phase happens when you lower the weight back to the starting position; the biceps muscle is controlling the descent and slowly lengthening.

This lengthening under tension is crucial for muscle development and can help improve strength, flexibility, and overall performance. The eccentric phase is often associated with greater muscle damage, which can lead to hypertrophy (muscle growth) as the body repairs the tissue. Understanding this phase is essential for designing effective training programs and for rehabilitation, as it plays a key role in correcting muscular imbalances and increasing overall functional capacity.