"Up and at em" is a motivational phrase that encourages people to start working hard and pursue their goals. However, there are several synonyms that can be used interchangeably to express the same sentiment. One such synonym is "rise and shine", which means waking up and starting the day energetically. Another synonym is "hit the ground running", which implies starting a task with full force and determination. "Get cracking" is yet another synonym that can be used to urge someone to begin an activity without delay. Hence, these interchangeable idioms can be used to boost the morale and motivation of those around us.