During a fight, you only have one meter under your name, that is the power meter. Your opponent has one likewise. Watching your power bar can tell you a lot about which way the fight is headed, either it's full and you can take more punches and punch more powerfully or it's low and you're in trouble. The same goes for your opponent's power bar, watching when to take them down or when to block.
Between rounds, you get a chance to freshen up and get some last minute coaching. During the one-minute interval, your power will go up only half of what has been drained.