We most commonly associate stretch marks with pregnancy, but there is another group that can also be more likely to develop them.
Bodybuilders aim to create bulk quickly, as they increase their muscle mass. Stretch marks can occur anywhere on the body, although bodybuilders often find them appearing under the arms where the muscles of the upper chest and front shoulder meet.
While stretch marks are not dangerous, these purple or red marks indicate that the dermal layer beneath the epidermis can no longer keep up and accommodate the increasing mass of muscle. The skin has been stretched beyond its elastic capacities and damage results.
As the body begins to repair the damage it produces scar tissue. Scar tissue contains less collagen and is more fibrous than normal, healthy skin. This makes it less elastic and gives it an appearance different from that of the surrounding tissue. While the colour of the stretch marks usually fades over time to a silvery grey, the marks never disappear completely.
Appearance is important to bodybuilders and extensive stretch marks can cause embarrassment. Stretch mark removal using a combination of microdermabrasion and laser therapy can effectively reduce the appearance of these marks.