Weighted Bicycle Crunch

Lie on your back with your hands holding a light weight against your chest and your knees pulled in at a tabletop angle. Rotate to bring one elbow toward the opposite knee while the other leg extends out straight, then switch sides in a slow pedaling motion. The weight against your chest adds load to the twist itself, so keep the movement controlled rather than swinging through it with momentum. Keep your lower back pressed toward the floor throughout and lead the rotation with your ribs turning toward your hip, not your elbow reaching for your knee. Extending the working leg fully is what keeps your hip flexors and core sharing the load evenly.