Abs

Abs, short for abdominal muscles, are a group of muscles located on the front and sides of the torso that support trunk movement, posture, and various bodily functions. The principal muscles commonly included are the rectus abdominis, which runs vertically along the front of the abdomen; the external oblique on the outer sides; the internal oblique beneath it; and the transversus abdominis, the deepest layer that encircles the abdomen.

Functionally, the abdominal muscles flex and rotate the trunk, stabilize the spine, and increase intra-abdominal pressure during lifting, coughing, defecation, and childbirth. They also play a role in respiration, especially forced expiration, and in maintaining posture while standing or moving.

Anatomically, the rectus abdominis is divided by horizontal tendinous intersections, creating the “six-pack” look in those with low body fat. The linea alba runs down the midline, separating the left and right sides of the rectus. The oblique and transversus muscles form a layered wall that supports the core. The nerves supplying these muscles come from the thoracoabdominal and first lumbar nerves; blood supply is through the superior and inferior epigastric arteries.

Visible abs depend on body fat percentage and genetics in addition to muscle development. Training typically emphasizes core stability and strength through exercises such as planks, leg raises, and crunch variations, often alongside compound lifts. Proper technique and progressive overload are important to reduce injury risk and improve functional performance.