Lie flat on your back on a mat with your arms by your sides or under your hips for support. Place a medicine ball between your feet or ankles and squeeze it firmly to keep it secure. Engage your core and raise your legs together until they form about a 90° angle with your torso while keeping them straight. Pause briefly at the top, then slowly lower your legs back down toward the floor without letting them touch, maintaining constant tension in your abs. Repeat for the desired number of repetitions with controlled movement.
Log your medicine ball lying leg raise sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.