Bdellovibrio bacteriovorus is a predatory bacterium that may serve as a living antibiotic by destroying biofilms and invading gram-negative bacteria. Swimming at over 100μm s-1, these predators collide into their prey and invade them to complete their life cycle. While previous experiments have investigated B. bacteriovorus’ motility, no study has yet collected swim speed variations over the lifespan of B. bacteriovorus. In this study, we used state-of-the-art bacterial tracking methods to record the speed of tens of thousands of bacteria. These results were used to describe their metabolic state under starvation conditions in which they lose energy in a dissipative manner by propelling themselves at high speeds through solution. In particular, we investigated the metabolic response of starved predators to the addition of prey-lysate.