Sat up, a phrase that describes a change in position from a reclining or lying position to a sitting one, can be expressed using a variety of synonyms. "Roused," "aroused," or "awakened" can imply the movement from a lying down to a sitting up position, while "perked up" or "straightened up" convey a sense of alertness or attentiveness. "Erected," "rose," or "stood up" could also refer to a change in position from a sitting to a standing one. All of these synonyms convey various nuances of posture and position, but each can effectively communicate a change in physical position from a reclined position to a sitting or standing one.