Barbell one leg squat

Stand with your feet shoulder-width apart and hold a barbell across your upper back. Lift one foot off the ground and extend it forward, keeping it parallel to the ground. Bend your standing leg and lower your body down as if sitting back into a chair, keeping your chest up and your back straight. Lower yourself until your thigh is parallel to the ground, then push through your heel to return to the starting position. Repeat for the desired number of repetitions, then switch legs and repeat.