Any exercise or any technique that causes the muscles underneath the skin to grow at a rapid rate will stretch the skin very tight and open the door to stretch marks. Weight lifting and other body building exercises make the skin too confined for the body parts it is holding. This results in the tearing of that skin in the dermis (middle layer) which proceeds into the epidermis (outer layer) of the skin. The skin breakage (or tearing of the connective tissue in the skin) will result in the production of stretch marks. Some of this may be avoided or prevented with an application of creams such as Verum and Trofolastin. These contain Vitamin E, collagen, elastin, pathenol and Centella extract. stretch marks