Decisions depend on the reward at stake and the effort required. However, these same variables influence the vigor of the ensuing movement, suggesting that factors that affect evaluation of action also influence performance of the selected action. In this talk, I will describe a mathematical framework that links decision-making with motor control. Each action has a utility that combines the reward at stake with its effort requirements, both discounted as a function of time. The critical assumption of this model is to represent effort via the metabolic energy expended to produce the movement. I will show that a single mathematical formulation of action predicts both the decisions that animals make as well as the vigor of the movements that follow. This framework accounts for choices that birds make in walking vs. flying, choices that people make in reaching and force production, and the curious fact that pedestrians walk faster in certain cities. I suggest that decision-making and movement control share a common utility in which the expected rewards and the energetic costs are discounted as a function of time.