Instead of breathing into your chest, take air into your belly, inflating it like a basketball. This will stabilize your entire midsection. To belly breathe, take a deep breath while forcefully pushing your belly out. This should help you use your diaphragm to draw air into your belly. During the lift, try to exhale forcefully against your closed throat. This action, called the Valsalva maneuver will help you build up enough pressure to stabilize yourself under big weights.