To stretch a muscle, it should be put in a position that produces a slight pull on the muscle but not to the point of pain. With a static stretch, the position in which a slight stretch is felt should be held 15-30 seconds, and each stretch should be repeated 3-5 times on each side of the body. The primary note regarding stretch position is that it should not cause pain or take the joint past the normal range.
There are several forms of dynamic stretching, with the key difference being that dynamic stretches take the joint and muscles through the full range of motion, often repeatedly.
ACSM guidelines recommend that stretching activities be done at least two days per week.”
Author: A. Lynn Millar, P.T., Ph.D., FACSM