Obliques

The external oblique is the most superficial of the lateral abdominal muscles. It originates from the last eight ribs and inserts on the linea alba, the pubis, and the iliac crest. The internal oblique sits beneath the external, originates from the thoracolumbar fascia and the iliac crest, and inserts on the last ribs and the linea alba. When you rotate the torso to the right, the left external oblique and the right internal oblique work together. This crossed co-contraction is the key to trunk rotation.

The most effective exercises for the obliques are the Pallof press, cable rotations (woodchop), side crunches, the side plank, and single-arm farmer's walks (suitcase carry). The Pallof press trains the obliques in anti-rotation, that is, it forces them to resist a force that's trying to rotate the trunk. This type of work is particularly functional and transferable. Crunches with rotation and Russian twists train them in a more dynamic way.

A common doubt: does training the obliques widen the waist? No, unless you use extreme loads for endless sets. Direct oblique work with normal volumes strengthens the core, improves stability in compound movements, and defines the lateral line of the abdomen. Strong obliques protect the spine during rotations and lateral flexions of daily life. Include them in your ab routine: 2-3 sets of one anti-rotation exercise and one of lateral flexion are enough.