Weighted Stability Ball Crunch

The weighted stability ball crunch is a core exercise performed seated on a stability ball, holding a weight against your chest while you lean back and curl your torso up. Adding load turns a bodyweight crunch into a strength movement for the rectus abdominis, and the unstable surface forces the obliques and deep stabilizers to work through every single rep. What makes it different from a floor crunch? The ball lets the spine extend slightly at the bottom, so the abs move through a longer range instead of stopping where the floor stops them. Who should use it? Intermediate and advanced lifters who already own clean bodyweight crunch mechanics. How much weight? Most people start with a single five- to ten-pound plate held at the chest and work in sets of twelve to fifteen controlled reps, keeping the knees bent and the feet planted.