Bodybuilding Stretch Marks

What causes bodybuilding stretch marks? Simply, skin is made up of collagen and elastin fibers, a protein mesh in the skin that makes it flexible and able to stretch and recoil back to its original position. When bodybuilders are building muscle mass and putting on weight too quickly.The skin tears and results in scar tissue known as "bodybuilding stretch marks" or "striae" http://www.delicious.com/Youserainvid/bodybuilding