Crunches with twists to knee opposite

Rotate the torso under control through the rib cage and waist while keeping the pelvis as stable as the variation allows. Return without bouncing. Keep the same range from repetition to repetition instead of speeding up as you fatigue. Breathe continuously and end the set before technique starts to break down.

Choose a resistance that lets you preserve technique from start to finish. You should feel most of the work in abdominals and obliques; if you feel sharp pain, joint pinching or a clear loss of control, reduce the load or range and stop if symptoms persist.