“With remobilization, tendons and ligaments recover their structural and material properties” {3}. This is a quote from a scientific study on ligaments and tendons in the body. In other words, with exercise, tendons and ligaments rejuvenate to their original shape and condition.

What causes facial sagging?

As we age the ligaments of the face stretch and become longer. {1} This is one of the reasons our faces sag and droop as we age. The subcutaneous layer of fat in the face lies within relatively consistent anatomical compartments that are separated by connective tissue and a thin layer of organic material, laminae.
Please go here, to read the full explanation, view the footnotes and see the graphic!