How To Exercise Without Moving A Muscle?

Isometric is the answer to your question.Isometrics are the strengthening exercises in which joint angles and the length of the muscle does not change during the contraction,without any visible contraction.It can be done for all the major muscle groups of the body.

Hi Lenin,
Lifemojo Expert is right. Isometric exercises are more helpful to improve your endurance of that muscle. For example: Doing squats and hold that position for 10 counts and slowly coming up and repeating the same exercises.