To execute a weighted backward lunge, hold a pair of dumbbells by your sides, standing with your feet hip-width apart. Step back with one foot, lowering your body until both knees form 90-degree angles, keeping your front knee aligned with your ankle. Push through your front heel to return to the starting position, alternating legs for each repetition to target the quadriceps, hamstrings, and glutes while also engaging your core for stability.