Beta blockers are drugs that block nerve impulses and reduce heart rate and force. They are used to treat conditions like high blood pressure but are also used in precision sports to improve performance by steadying nerves and improving accuracy. Common side effects include dizziness, drowsiness, and breathing problems. Beta blockers are most commonly used in gymnastics, diving, ski jumping, soccer, wrestling, shooting and archery because they help athletes remain focused and in control by reducing heart rate.