Place a barbell on the ground and lie supine under it so that it is directly above your hips with your hands grabbing it shoulder-width apart with an overhand grip.
With knees bent, exhale and push through your heels to extend your hips and raise the barbell, keeping your head firmly on the ground the entire time.
Continue until your upper legs and torso make a straight line, holding onto the barbell tightly so that it stays in place.
Inhale and lower the barbell back down to the floor, returning to the starting position.