Which of the following is a common cause of muscle soreness after exercise?

Eccentric muscle contractions are typically a common cause of muscle soreness following exercise, often referred to as delayed onset muscle soreness (DOMS). This type of contraction occurs when muscles lengthen while under tension, such as during activities like downhill running or the lowering phase of a squat. The microscopic damage to muscle fibers from these contractions leads to inflammation and the sensation of soreness that many people experience a day or two after a workout.

The reason this option is highlighted is due to the specific physiological response that occurs during eccentric activities. These contractions generate high force and can cause more muscle damage compared to concentric (shortening) or isometric (static) contractions. Consequently, this damage triggers a repair process that results in muscle soreness.

In contrast, while high carbohydrate intake, inadequate hydration, and protein deficiency can influence overall performance and recovery, they do not directly contribute to the acute muscle soreness caused by exercise. Carbohydrate intake is necessary for energy, hydration supports performance, and protein is essential for muscle repair, but none of these directly relate to the immediate muscular discomfort that follows eccentric exercises.