Mike has been training for his bodybuilding competition by lifting weights and doing exercises, such as sit-ups, to get that rippled, "washboard" abdomen look. what muscle provides those "rippled abs" that are sometime called a "six pack"?

That Muscle is called the Rectus Abdominis

Explanation: There is a thin line of connective tissues that separates this muscle that gives it that compartmentalized look. This line is called the Linea Alba. This muscle runs vertically on the anterior wall of the abdomen.

Hope it’s clear?