If a muscle shortens immediately after a stretch :

(A) Force and power output increases

(B) Energy expenditure decreases

(C) Endurance output increases

(D) Explosive power output decreases

Choose the correct answer from the options given below : 

Concept:

Stretch-shortening cycle (SSC):

• A stretch-shortening cycle (SSC) is an active stretch (eccentric contraction) of a muscle followed by an immediate shortening (concentric contraction) of that same muscle

Explanation:

In this cycle:

• Muscle force, work, and power output during concentric contractions (active muscle shortening) are increased immediately following an eccentric contraction (active muscle lengthening).
• This increase in performance is known as the stretch-shortening cycle (SSC)-effect.
• And decreases energy expenditure.
• Recent findings demonstrate that the SSC effect is present in the sarcomere itself.

Thus, If a muscle shortens immediately after a stretch a Force and power output increases but Energy expenditure decreases.

Additional Information:

• The stretch-shortening cycle (SSC) refers to the ‘pre-stretch’ or ‘countermovement’ action that is commonly observed during typical human movements such as jumping.
• This pre-stretch allows the athlete to produce more force and move more quickly.
• Though there is controversy surrounding the mechanics responsible for the performance improvements observed from using the SSC,  it is likely to be a combination of the active state and the storage of elastic energy within the tendon.
• Due to the negative effects of the electromechanical delay, it may be suggested that training methods which improve muscular pre-activity, such as plyometric and ballistic training, may be beneficial for improving athletic performance