Weighted Glute Kickback

Same hands-and-knees setup as the bodyweight kickback, but now a dumbbell sits in the crease behind your knee, held there by keeping your leg bent as you lift. The extra load means your core has to work harder to stop your hips from rocking or your lower back from arching to compensate. Drive through the heel and squeeze the glute to lift the thigh in line with your torso, keeping the dumbbell trapped behind the knee the whole way. If it starts to slip, your knee angle is opening too much — reset before adding more weight than you can control.