Lie on a decline bench with your feet secured under the pads and hold a dumbbell against your chest. Engage your core and lift your torso upward toward your thighs using your abdominal muscles. Pause briefly at the top, then slowly lower your body back down in a controlled motion. Keep your core tight and avoid pulling with your neck or using momentum.
Log your dumbbell decline sit up sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.